33is

PROCEEDINGS

XVIIT INTERNATIONAL CONFERENCE ON COORDINATION CHEMISTRY

•July 18-23,' 1977 Sao Paulo, Brazil PROCEEDINGS

XVIII INTERNATIONAL CONFERENCE ON COORDINATION CHEMISTRY

July 18-23, 1977 Sao Paulo, Brazil

Sponsors Brazilian Academy of Sciences International Union of Pure and Applieu Chemistry University of Sao Paulo XVIII ICCC SCIEN1

Scope Organized by

Brazilian Academy of Sciences will 1

Organizing Committee

P. Senise, Sao Paulo (Chairman) E. Giesbrecht^ Sao Paulo S. Mathias, Sao Paulo L. Hainberger, Rio de Janeiro A.C. Spinola Costa, Bahia E.3. Paniago, Belo Horizonte N. Valle Silva, Rio de Janeiro (Treasurer)

Krumh

Local Executive Committee P. Kr P. Senise (Chairman) E. Giesbrecht S. Mathias (Editor) G. Vicentini O.A. Serra Plena H. Li Chum Appli SCIENTIFIC PROGRAM

Scope

Plenary lectures, section lectures and contributed papers will be presented under five topics:

I - Organometallic Compounds II - Mechanisms of Reactions of Complexes III- Structure and Stereochemistry of Coordination Compounds IV - Application of Coordination Compounds in Ana- lytical Chemistry V - Lanthanide Chemistry

Krumholz Memorial Session

A special session honoring the memory of the late Professor P. Krumholz will be held on Tuesday, July 19, 1977.

Plenary lectures will be published in the IUPAC Journal Pure and Applied Chemistry. The

Monc 11:1 E.O. Prep plea

Tues 11:1 H. T Che

Thu PLENARY LECTURES 11: S. The con

Thu 17: H.M App

Fri 11: E. Coo (X-

--••, n.ira^ The plenary lectures will take place in Room A

Monday, July 18,1977 11:15 - 12:15 h E.O. Fischer, Munich (GFR) Preparative and structural aspects of transition metal carbyne com- plexes

Tuesday, July 19, 1977 11:15 - 12:15 h H. Taube, Stanford (USA) Chemistry of (II) and (II) ammines

Thursday, July 21, 1977 11:15 - 12:15 h S. Kirschner, Detroit (USA) The pfeiffer effect, outer-sphere complexation, and the absolute configuration of coordination compounds

Comb" Thursday, July 21, 1977 17:00 - 18:00 h vari H.M.N.H. Irving, Leeds (UK) Application of coordination compounds in analytical chemistry disc

of t Friday, July 22, 197-7 11:15 - 12:15 h An o E. Giesbrecht, Sao Paulo (Brazil) Coordination compounds of rare earths with QnX+O type ligands meta (X=S,N,P,As) cati

—j >• •"'

PREPARATIVE AND STRUCTURAL ASPECTS OP TRANSITION METAL CARBTNE COMPLEXES E.O.Fischer Institute of Inorganic Chemistry, Technical University Munich, Arcisstrasee 21, D-8000 MUnehen 2, Germany A short introduction deals with the discovery of the first capbyne complexes of the type trans-Hal(CO)^MCR ( Hal = Cl, Br, Ij M • Cr, Mo, W; R = methyl, phenyl) in 1973, defined by its name as having a sp hybridised, atom triply bonded to a transion metal. A general survey then follows about presently known routes, to prepare carbyne complexes of uncharged and also ionic types, how t& modify them, and how to use them as starting materials for the introduction of the carbyne ligand into organic chemistry.

Examples will be mentioned especially for a) CO substitution, b) halogen substitution, c) additions of nucleophiles to the crb e' d) CR-substitution, e) preparation of organic molecules which contain the cleaved CR-ligand.

Combined with the preparative results x-ray structures of a great variety of such uncharged and cationic carbyne complexes will be discussed, and their importance for the determination of radii of triple bonded transition metals will be emphasized.

An outlook for the preparation of new carbene complexes of transition metals, based on addition reactions of anionic nucleophiles to cationic carbyne complexes, will complete the aspects of the field. ^CHEMISTRY OF RUTHENIUM(II) AND OSMIUM(II) AMMINES Henry Taube Department of Chemistry, Stanford University Stanford, California 94305 A motivation for the study of ruthenium(II) and osmium(II) ammines is that back-bonding is an important interaction in the complexes containing also unsaturated ligands. The pentaammine-unsaturated ligand species are usually substitution inert, a property which facilitates their characterization and so they provide a convenient opportunity for studying the interface between ligands which are regarded as characteristics of organometallic compounds, and the saturated ligands which figure in the chemistry of "classical" complexes. Thoy provide, as well, an opportunity for studying in a systematic way the effects of back donation on physical properties and reactivity. The chemistry of the ruthenium ammines has been the more thoroughly studied, and some of the salient observations made with them will be reviewed. Comparisons will be made with Fe(CN)_?~ (referred to by J. Malin as the poor man's ruthenium) and with Os(NEL) 2+. The osmium(II) ammines call for more elaborate preparative procedures than suffice for ruthenium(II) ammines, and current research on these complexes will be described.

,-vnJj.Ji^ Z/ THE PFEIFFER EFFECT, OUTER-SPHERE COMPLEXATION, AND THE $7 "APP1 ABSOLUTE CONFIGURATION OF COORDINATION COMPOUNDS H.M Stanley Kirschner

Department of Chemistry, Wayne State University Detroit, Michigan 48202 U. S.A.

The Pfeiffer Effect is the change in optical rotation of a solution of one enantiomer an optically stable compound (called the "environment" substance) upon the addition of a racemic mixture of an optically labile complex compound. The nature of the Effect will be described, along with evidence supporting the "equilibrium displacement" mechanism proposed for the Effect.

Further, the effect of Pfeiffer activity on the racemization and resolution of dissymmetric complexes is described, along with the application of the Pfeiffer Effect to the determination of absolute configuration of coordination compounds which are both optically active and optically labile. Still further, a proposal to describe the basic nature of the Effect at the molecular level is presented, which utilizes the concept of bonding of the environment substance to pi-electron cloud systems of the ligands of the complex.

With regard to dissymmetric, optically stable complexes, it has been shown that an interaction occurs between such complexes and environment substances when the latter are present in much higher concentrations than the former. A technique will be described which utilizes this phenomenon to predict the absolute configuration of dissymmetric, optically stable complexes, which is base.: upon a proposal of outer-sphere complexation through hydrogen bonding between the optically active environment substances and the ligands of the complexes. V / 7i "APPLICATIONS OF COORDINATION COMPOUNDS IN ANALYTICAL CHEMISTRY" C001 H.M.N.H.Irving TYP3 Erni Department of Inorganic and Structural Chemistry, University of Leeds, Leeds LS2 9JT, England and Department of Chemistry, Ins" University of Cape Town, Cape Town, South Africa. Cai: 0101

Coordination compounds have been used extensively in analytical chemistry for over 100 years. Examples of applications in absorptiometry, atomic absorption spectroscopy, chromatography (gas-solid, liquid-solid, high-pressure and tic), gravimetry, liquid-liquid extraction and titrimetry (especially complexometry), for separation and preconcentration, for ion-selective electrodes, and for the design of highly selective reagents will emphasise those characteristics (e.g. polarity, size, colour, hydrophobicity, stability, conformation etc.) relevant to particular uses. Examples of useful steric effects, of synergism and kinetically controlled separations will be included. COORDINATION COMPOUNDS OF RARE EARTHS WITH Q X TYPE LIGANDS (X = S, N, P, As). Ernesto Giesbrecht Instituto de Quimica, Universidade de Sao Paulo Caixa Postal 20780 01000 - Sao Paulo, SP, Brazil

An increasing number of complexes formed by

rare earths with Q X -»• 0 type ligands are

being reported in the literature. Sulphoxides,

phosphine and heterocyclic-N-oxides

are the more important representatives of

these typs of coordinating agents although

some complexes of seleno1oxides and arsine 1

oxides are also described.

The preparation, the properties and the more

impox^tant physical and chemical characteristics

will be reported.

SECTION LECTURES

M. To The t (Room

Thurs 10:20

1 t MICROCOPY RIMHUIDN II si l Il/Uil

10

Monday; July 18', 19 77 14:00 - 14:30 h E.Fluck, Struttgart (GFR) Prussian blue and its analogs (Room A) .

Monday, July 18, 1977 16:00 - 16:30 h B.J.-Trzebiatowska, Wroclaw (Poland) Antiferromagnetic and ferromagnetic phenomena and structure of coordination compounds (Room B)

Monday, July 18, 1977 17:20 - 17:50 h L. Sacconi, Florence (Italy) Recent contributions to the chemistry of 3d metals in low oxidation states (Room A)

Tuesday, July 19, 1977 10:20 - 10s50 h u.A. Koningstein, Ottawa (Canada) Eletronic Raman spectroscopy of some transition metal sandwich compounds {Room D)

Tuesday, July 19, 1977 17:20 - 17:50 h M. Tobe,London (UK) The trans effect. Some recent kinetic and equilibrium studies (Room C)

Thursday, July 21, 1977 10:20 - 10;50 h R.C. Mehrotra, Delhi (India) Coordination chemistry of lanthanides (Room C)

i ii •! ijt Y; 11

Thursday, July 21, 1977 PRUSSIAN B 15:00 - 15:30 h E. Fluck a G. Eichhorn, Baltimore (USA) Recent studies on the effect of metal ions on nucleic acid and Institute genetic information transfer Pfaffenwal

Thursday, July 21, 1977 A survey i 16:20 - 16:50 h and bondin J. Chatt, Brighton (UK) The reactivity of dinitrogen in its stable complexes [(C) (Room C) ml C6 New result Friday, July 22, 1977 10:20 - 10:50 h which have S.L. Davydova, Moscow (USSR) Atomic absorption spectrophotometric analysis of coordination with vfi = compounds with and without preliminary decomposition (Room C) bauer spec and t

Friday, July 22, 19 7 7 Mossbauer 14:00 - 14s30 h F.G. Gallais, Toulose (France) Charge transfer in coordination compounds: a study of Lewis coordinate acids of group III elements by means of nuclear resonance spectroscopy (NMR and NQR) Furthermor (Room A) spectrosco

Friday, July 22, 1977 the type F 16:00 - 16:30 h discussed. S.P. Sinha, Zurich (Switzerland) Application of the "inclined W" theory in predicting the sixth and the higher ionization potentials for the lanthanide series (Room D)

—.•j».^a^A jy

/ ANTIFERPf COORDINAT V 12 B. Jezows Institute PRUSSIAN BLUE AND ITS ANALOGS 50-383 Wi Rece E. Fluck and H. Inoue elect roni the probl Institute of Inorganic Chemistry, University of Stuttgart of the le Pfaffenwaldring 55, D-7OO0 Stuttgart 80, Germany phys i cal -VanVleck a compose A survey is given of the present knowledge on the structural chemistry The and bonding properties of Prussian blue and its analogs of the type seeirs to s y s t em s , M^[MB(CN) ] .xH O, especially^ MB(CN) ] -xH O and M^[MBCCN) ] «XH O. The direc 6 n 2 6 2 2 6 3 2 now more The inter New results will be reported on compounds of the type M M (CN)fi com IT ore fr which have not been studied to great detail as yet. In the compounds The case when such syst with M = Fe and M = Co, Rh and Ir both the infrared and Moss- angular s magnetic bauer spectra substantiate the existence of chemical bonding between has been comp1 exes iron and the atoms of the ligands. Similarly, superexch of spin s Mossbauer and X-ray photoelectron spectra show that the compounds evi den ce an intere Fe|Fe(CN)5x]-xH2O (X = H20, NH3 and CO) contain low spin Fe(II) centre of coordinated by carbon, and high spin Fe + coordinated by nitrogen. The the ani so br Furthermore, the results of Mossbauer and X-ray photoelectron mole cule cons i dera spectroscopical investigations on the isomorphous compounds of the elect

B B the syste the type Fe [M (CN) L.XH20, where M is Fe, Ru or Os, will be The developed discussed. for bette iragneti c And po lynucle

1 13

ANTIFERPOMAC-NETIC AND FEPRn«ACNETIC PHENOMENA AND STRUCTURE OF RECENT ( COORDINATION COMPOUNDS LOW OXH B, Jezowska-Trzebiatowska Institute of Chemistry, University of Wroclaw L. Sacc< 50-383 Wroclaw, Joliot-Curie 14, Poland Institui Recently, the rapid development of studies on molecular and Via J. 1 electronic structure of a substance has been observed. In that connection the problem of elucidation of the structure of complex compotras is one Comp: of the leading probleirs in chemistry, The combination of versatile are ratl physical methods theoretical quantum chemistry an Heissenberg-Dirac- -VanVleck methods allows the penetration into the structure of such The lig« a composed systems. The problem of bondinp and interaction among the metal atoms strong i seems to be essential for understanding of the formation of polynuclear systems, so important in nature and in different types of materials. tris(di] The direct bondings amonp the metal atoms were considered as very rare, tris(2-< now more and more proofs are being found for such a stronp interaction. The interaction via other atoms of higher e lectronegativity are moie and tri! comtrorc frotr which the oxypen and sulphur bridges are the most important. The extreme antiferromapnetic interaction has been found ina be part: case when oxypen atom forms the linear bonding between metal atoms. In such systems the complete spin decay of metal atoms occurs, while in ligands, anpular systems it is only partial. .To explain the electronic structure, ligands magnetic and spectroscopic properties_ of bridged systems the MO theory has been applied. That allowed' fo anticipate the properties of the new alkylsu: complexes and to discover the direct V-M interaction besides of the superexchange one in double bridpec! dimers. The conf orma t i onal analyses type an of spin states of dimers by the AOV method provided the evidence of the eqilibriutn between the singlet and triplet states and Attei an interestinp piece of information about the structure of the active centre of nitrogenase. are the The investigations of the isotropic exchange interactions and of vhich tl the anisotropy of j_pi_n-spin interaction in the wide ranpe of the bent oxygen bridpe direct oxygen and OP bridges R-residue of the organic In the < molecule complexes by the magnetic and ESP method and theoretical consideration based upon the Heisenberp model allowed deeply recognize hedrall: the electronic structure and antiferro- and ferromagnetic specifity of the system. phospho: The study of the exchange and superexchange interactions has been developed as the essential not only for the complex compounds but also to the i for better understandinp of the biological role of metals and of the The ] magnetic phenomena in rrolecular systems. And that was why we have extended our studies as to comprise the derivat: polynuclear and cluster systems. formal <

I 14

RECENT CONTRIBUTIONS TO THE COORDINATION CHEMISTRY OP 3d METALS IN Electroni LOW OXIDATION STATES L. Sacconi J. A. Kor Institute of General and Inorganic Chemistry University o£ Florence Departmen Via J. Nardi 39 50132 Florence Italy Carleton, Complexes of and in oxidation states lover than tvo T are rather rare, with the exception of carbonyl and arene complexes. of electr The ligands capable of stabilizing such complexes have generally a (electric strong-it-acidity. The polytertiary phosphines and arsines as 1,1,1- spectral arise fro tris(diphenylphosphinomethyl)ethane, p , the analog, as., The Raman tris(2-diphenylphosphinoethyl)amine, np , the arsenic analog, nas. have stud and tris(2-diphenylphosphinoethyl)phosphine, pp_, have been shown to and in (C be particularly veil suited to this goal. They can act as ancillary Emphasis ligands, the coordination polyhedron being completed by other susceptib is couple' ligands such as halides, cyanide, hydride, hydrogensulfide, sulfide, obtain thi alkylsulfide, etc. Several cobalt(l) and nickel(I) complexes of this CgHg ring: type are reported. They are generally four, or five-coordinated. electronii Attention is focussed on a number of dimeric species. Among these + are the complexes [(p3)Co(SH)2Co(p3)] and f.(P3)Co(SH)2Co(p3)] in vhich the cobalt exibits the formal oxidation numbers 1 and 1.5. In the dimeric complex [(np )Co-S-Co(np,)] the d cobalt is tetra- hedrally coordinated to the bridging and to the three atoms of the ligand, the apical nitrogen not being bound to the metal. The potentially bidentate 1,8-naphthyridine and some methyl derivatives form dimeric complexes of nickel and in the formal 1.5 acting as bimetallic bridging ligands.

I Vfi 'A ;•' £' 15 _' v' v' •-:, Electronic Raman Spectroscopy of some transition metal sandwich compounds. J. A. Koningstein Department of Chemistry Carleton, University The energy level diagram of many sandwich complexes reveal the presence of electronic states which are <2000 cm" above the ground state. The direct (electric dipols) transitions are neither active in the far infrared and infrared spectral regions. This because the transitions are between electronic states which arise from the same electronic configurations and only Raman transitions are allowed. The Raman tensor operator is of the form a and is even. During the last year we have studied several electronic Raman effects of transition metal ions in solids and in (CgHg^Tm complexes and in this talk some of our results shall be discussed. Emphasis shall be placed on the relation of the electronic Raman data and magnetic susceptibility of the compounds. Also we found that the ring torsional mode is coupled to the low lying electronic states and from the data we were able to obtain the potential surfaces. It shall be shown that the relative position of the CrHc rings is very sensitive to the type of compounds and a small change in electronic energy can result in rather large changes in these relative positions. 16

THE TRANS EFFECT. SOME RECENT KINETIC A.";. EQUILIBRIUM STUDIES.

M.L. Tobe.

Chemistry Department, University Collog..-, Gower Street, London, W.C.1.

England.

The kinetics of the forward and reverse rej-.~t.ion.•,

+ am l L am] + Cl"

(L = R S, R SO, R-P anri C'.y ; an. = rirnine) :ia;- b'.-.n studied in methanol at 30°C.

and the rate constants a.*:.l .- niilibr;. >juii •-•ontsi.ants will be discussed as functions 01"

the nature of L aria am. Once ...oivolytic >i . • .irhancec and mass-law retardation

effects have been avoids, the asua^. tv.o Lorrr. rat.. -±aw, k , = k. + k_,[N] obs I d.

(K = a;n or Cl ), iu observe-.! s.-w the relative importance of the k and k_

contributions are found to depend very much upon the nature of the substrate

and especially upon the nature of the trans ligand, L. For the strong ground state

trans-effect ligand, PEt_, the k- pathway dominates the substitutions, while

for L = Me^SO the k contribution can be insignificant. The rate constants

for the entry of amines are not very sensitive to basicity but there is a small

but significant inverse basicity dependence for heterocyclic amines where the least

basic is the most reactive. The effect is most pronounced for L = PEt., where the

slope of the linear plot of log k, vs pK_ of amH is - 0.2. Both k, and k_ LnS

for the reverse reaction and, in consequence, the equilibrium constant have a

strong dependence on the basicity of the displaced amine, the complex with the least basic amine being the most labile. The extent to which information of this

jort can be used to distinguish between ground state trans effects and transition

state trans effects and to assess their relative contributions to the reactivity

of the substrate will be discussed. 17 COORDINATION CHEMISTRY OF LANTHANIDES • c R.C. Mehrotra RECENT STUD] v TRANSFER £ ol Vice-Chancellor, University of Dellii, G. L. Eichhc '}' £' Delhi-110007 (India) and Y. Shin Gerontology Coordination Chemistry of Lanthanides has received considerable attention Hospitals, I n during the last few years. Some of its special characteristics are: (i) 4f 0 5s , p° We have type of electronic configuration of Lnn+ ions, with the 4f electrons being largely donor groups unavailable for bond formation, (ii) large (but diminishing with atomic number) with differs size of the ions, which minimises the electrostatic attractions for the llgands, structure oi (iii) high coordination numbers upto 12, (iv) ligand lability, (v) hard acid of the phosj character of the cations leading to preference for oxygen or nitrogen ligands, in a way ttu and (vl) competition of the ligands with water and hydroxide ion. The efi monomeric cc A number oi new coordination compounds of lanthanides have been synthesized information substitutiot in our laboratories by the reactions of lanthanon isopropoxides with ligands like in wrong coi (a) higher alcohols (ROH), (b) glycols (G(OH)2), (c) carboxylic acids (RCOOH), tions of ioi (d) aminoethanols (H2NCH2CH2OH, HN (CH2CH2OH)2 and N( CH2CH2OH)3), ion concent! (e) oxine (CQH^OH), (f) B-diketones and ft-ketoesters (HA) and (g) trimethyl- The efi

silanol (Me3SiOH). As the isopropanol liberated in the reactions can be removed polymerase. azeotropically with benzene, the reactions can be carried out in different molar contained ii ratios. These reactions thus provide novel and convenient routes for the synthesis same inform, i i required foi of mixeJ ligand derivatives also of the type: Ln(OPr )3_n(OR)n; Ln(OPr )(O2G); monomers; o] i Ln(OPri)3.n(OOCR)n; Ln(OPr )3.n(OCH2CH2NH2)n; Ln(OPri)3_n( A)n and Mg2+ and Co' Ln(Co,H6NO)n(A)3_n. Apart from spectroscopic studies, the identity of some of and deoxynui

these mixed ligand derivatives, e.g. Ln( CgH^NO)n(A) 3_n, has been established monomers of by their in organic solvents whereas the tris-oxinates are insoluble. of the etizyi A notable success or this novel route has been the synthesis for the first time complex. Tl Mn comple: o- anhydrous tris-B-diketonates of lanthanides; the products from aqueous ribo- and di solutions are always hydrated and are hydrolysed during attempts at dehydration RNA synthes even under reduced pressure. for correct The ef: Another novel series of derivatives synthesised can be represented by the partici] pri pri") nucleotide 1 are requirei ', (where L n=Sc, V , La, Ce, Pr, Nd, Sm, Gd, Tb, Dy,Ho, Er, \ b or Lu; wrong amino o and M ~ A\ or Ca). pairing of I Pr*- Evidence fo- favors "cor- These are volatile and soluble in organic solvents, in which they depict mispairing. monomeric behaviour. Some o: transfer cot Light has been thrown on the structures of all the above derivatives by We have reci interchange reactions with a variety of ligands as well as by i.r,, n. m. r. highly coopi and mass spectroscopic studies. of nucleic i We have als< in DNA-proti nucleus. It is i by complexii information ' i

' ':•. J

RECENT STUDIES ON THE EFFECTS OF METAL IONS ON NUCLEIC ACIDS AND GENETIC INFORMATION RE; TRANSFER G. L. Eichhorn, J. J. Butzow, P. Clark, J. Froehlich, J. Pitha, G. Rao, J. M. Rifkind v J. Chat and Y. Shin Gerontology Research Center, National Institutes of Health, NIA, Baltimore City Unit of Hospitals, Baltimore, Maryland 21224, USA Univers We have previously shown that the nucleic acid molecules contain many electron In gene donor groups, that metal ions can react with all of these groups, and that reaction but ne\ with different donor groups to many different dramatic changes in the known. structure of these genetic molecules. For example, metal ions catalyze the cleavage to the of the phosphodiester bonds of RNA, and they change the specificity of the enzyme DNase and chi in a way that can be predicted from metal binding to DNA substrate. of the The effects of metal ions on the structure of the nucleic acids and their monomeric constituents represent potential pathways for the deterioration of genetic and/or information transfer. Metal ions are required in all stages of this transfer, but the compour substitution of the wrong metal ions or even the presence of the essential metal ions series in wrong concentrations can to undesired results. Wrong metal ions or concentra- the aci tions of ions may come to cellular nucleic acids from the environment; in fact, metal the con ion concentrations in cells change with age. protona The effect of wrong metal ions is illustrated by recent studies with RNA the liq polymerase. This enzyme is a catalyst for the transcription of the genetic information reactic contained in the nucleotide base sequence of DNA into RNA molecules which carry the complex same information from the cell nucleus into the cytoplasm. Ms , Co^+ or Mn^+ are and wha required for the synthesis of RNA molecules from ribonucleotides, t'.ie correct RNA discuss monomers; other metal ions do not work. Of the three active metals, however, on]" Mg2+ and Co^+ appear capable of effectively differentiating between ribonucleotides and deoxynucleotides. Mn causes some error incorporation of deoxynucleotides, the monomers of DNA, into RNA. UV and ORD studies reveal that the CQ2+ and Mg2+ complexes of the enzyme undergo a denaturing transition at a different temperature than the Mn^+ complex. These results suggest that the Co~+ and Mg2+ enzyme complexes, but not the Mti^ complex, have conformations sufficiently sensitive to the differences between ribo- and deoxy- nucleotides. Cis PtCN^^C^ bound to DNA has yet another effect on RNA synthesis in that the size of the RNA molecules produced is smaller than required for correct information transfer. The effect of too high concentrations of essential metal ions is illustrated by the participation of Mg^+ in protein synthesis, which involves a translation of the nucleotide base sequence of RNA into an amino acid sequence of protein. Mg^+ ions are required for synthesis, but an excess of Mg leads to the incorporation of the wrong amino acids. We have postulated that such errors can result from the mis- pairing of nucleotide bases in the reaction between messenger and transfer RNA. Evidence for this hypothesis comes from the demonstration that low Mg^+ concentration favors "correct" Watson-Crick base pairing, and high Mg^+ does in fact lead to mispairing. Some of the potentially most damaging effects of metal ions on genetic information transfer could result from the c.rosslinking of nucleic acid strands by the metal ions. We have recently studied the mechanism of such crosslinking by Cu^+ ions and found that highly cooperative binding of Cu^+ to nucleic acid strands causes the disintegration of nucleic acid structure through both intramolecular and intermolecular crosslinks. We have also shown that metal ions rearrange the ordered packing of DNA molecules in DNA-protein complexes such as those that compose the chromatin of the cell nucleus. It is thus apparent that the changes induced in the structure of the nucleic acids by complexing metal ions can influence the function of these molecules in genetic information transfpr.

i •». >L 19

^ REACTIVITY OF DINITROGEN IN ITS STABLE COMPLEXES •\ c J. Chatt Unit of Nitrogen Fixation, School of Molecular Sciences, University of Sussex, Brighton, East Sussex BNl 9QJ, U.K. Institi In general, dinitrogen is not activated by ligating a transition metal, but nevertheless a number of reactions of ligating dinitrogen are known. The most reactive dinitrogen complexes are f..ued by elements One of to the left of the transition metal series in the , measurn and Groups. Dinitrogen complexes of molybdenum and of the general type [MfN^) ^ (PR3) 4 J react with acids to give ammonia methods and/or hydrazine and with organic halides to give organonitrogen and inc compounds. For the latter reaction light is needed in the tungsten by us f series only. The course of the reaction and products depend upon the acid or alkyl halide used and the nature of the other ligands in /organic the complex. The reactions with acids appear to be simple N •? as well protonations yet are affected greatly by the type of acid used and the ligands other than dinitrogen in the complex. The alkyl halide -- AAS for reaction involves the induction of free radicals by the dinitrogen been de complex from the alkyl halide. Recent developments in this field and what is known of the mechanisms of the reactions will be methyli discussed. time wi AAS of were cc The met regress concent has bee in depe compour It was metal c comparj 20

AS- ANALYSIS OF COORDINATION COMPOUNDS WITH AND WITHOUT PRELIMINARY DECOMPOSITION S. L. Davydova Institute of Petrochemical Synthesis of Ac.Sci.,Moscow,USSR

One of the most perspective(simplicity-of determination, accuracy of measurment, selectivity and sensibility towards elements) of modern methods for determination in minerals, petrols, foods and other organic and inorganic materials - atom-ab*txbtie>n spectrophotometri* was used by us for analysis of metals ir. different coordination compounds with •'/organic ligands (ketoesters,diketons,Schiff-bases,aminoacids and so on) , -"'-•'as well as polymer analogues of ligandsmentioned. - AAS for determination of Ni,Zn,Co,Cu and other transition metals has been developed in organic solutions (dimethylformamid,methylethylketon, methylisobutylketon and others) of coordination compounds,for the first time without preliminary decomposition of latters. Different variants of AAS of coordination compounds with and without preliminary decomposition were compared. The method of presentation of experimental data, based upon the regression line srow in coordinates specific absorbtion - solution concentration and permited to find the optimal region for concentration, has been given. The kinetics of process of metal concentration change in dependans on storage time for organic solutions of coordination compouns of transition metals has been studied. It was shown, that atom-absorBtion spectrophotometr^f as the method of metal determination in coordination compounds has many advantages in comparison with other instrumental methods.

that 21

CHARGE TRANSFER IN COORDINATION COMPOUNDS : A STUDY OF LEWIS ACIDS OF GROUP III 4 ELEMENTS BY MEANS OF NUCLEAR RESONANCE SPECTROSCOPX (NMR AND NQR). Fernand G. Gallais Laboratoire de Chtmie de Coordination du Centre National de la Recherche Scientifique, P.O. Box 4142, 31030 Toulouse Cedex, France.

The formation of a donor-acceptor or dative bond may be said to be a characteris- tic and fundamental feature of coordination chemistry. If the nature of this bond has been the subject of long-lasting controversies, it is now well known that it is a covalent one which, owing to its peculiar way of formation, has a high degree of po- larity. In other words, when coordination occurs, a relatively high charge transfer takes place between the donor and the acceptor entities. This fact has now been well established through quantum mechanical calculations but, although some experimental evidence has already been brought up in that field, there certainly remains a need for other proofs of the charge transfer phenomenon. Nuclear resonance spectroscopy seems to offer a good tool for that purpose as the results so obtained are directly affected by the nature of the electronic environment of the nuclei. This is obvious for NMR in terms of screening effects and is also true for NQR since the electronic charge distribution around the nucleus exerts a strong influence, through the electrostatic field gradient, on the quadrupole coupling constant. In fact, changes in nuclear resonance frequency may be easily related to changes in the atomic charge. For these reasons a comprehensive study of the molecular adducts of the chlorides of B elements of group III with various Lewis bases offering 0, S, N, P or As as donor atoms has been conducted with the help of NMR and NQR spectroscopy. For NMR the modifi- cations of the effective electronegativity and charge of the donor atom have been de- duced from the internal shifts of the protons. For NQR, information regarding the elec- tronic charge of the acceptor atom has been obtained through the observation of the 35C1 and *>9Ga resonance frequencies. Similar information has also been obtained for the donor atom 75As. The essential conclusion of Chis research is that in the above mentioned series the charge transfer is a regular and important phenomenon. This is proved just as well by the increased charge of the acceptor X which is responsible for a higher ioni- city of the X-Cl bond as by the decrease in the donor charge which leads to a larger internal shift of protons. On dhe other hand, it appears clearly that the "strength" of a Lewis acid or base is not an individual parameter inasmuch as it always depends on the nature of the rea- gent to which this acid or base is confronted. Now the order in which the group III elements must be placed with regards to the "acid strength" of their chlorides, i.e. : Al < B < Ga, does not follow the order in which they appear in their vertical group nor the order of their electronegativities ( Al < Ga < B ). Finally, it seems that Ga, and to a lesser extent Al, form stronger bonds with As, with P and even with S than with N and 0. This might mean that the period of the clas- sification to which an atom belongs is more important than the group, perhaps because the charge transfer going with coordination is easier when the energy levels involved in the donor and acceptor are relatively close one to another. From a more general point of view it becomes obvious that it may be regretted that the use of the name "Charge transfer complexes" be practically restricted to compounds which hardly deserve to be called complexes and whose formation does not usually correspond to a significant charge transfer. . • - . I

22 • ' /

APPLICATION OP THE "INCLINED W" TESORY IN PREDICTING THE SIXTH AND THE HIGHER IONIZATION POTENTIALS FOR THE _LAWTHANII>E_ SERIES Shyama P, Sinha Eidgenb'ssische Technische Hochschule, Laboratorium fiir Biochemie, Universitatstrasse 16, CH-8092 Zurich, Switzerland THE energy level structure of the lanthanidesin different oxidation states are very complex. Reliable experimental values for the first(lP^) and the second(lP2) ioni- zation potentials for all lanthanides are available[c.E. Moore, Ionization Poten- tials and Ionization Limits derived from the analyses of Optical Spectra, NSRDS- NBS 34 (197C) and the references therein]. Experimental values for the third(lP3) and the higher IP's are rather scarce. Higher IP values, upto IP4, have been em- pirically obtained by several workers. Sugar[J.Opt.Soc.Aner. 65,1366 (1975)] has recently calculated the fifth(lP5) potentials using the relationship [IP = SD + SB +8 + TJ. However, the ''irregular behavior" of the quantities SD and AE as a function of the number of f-electrons introduces the major source of uncertainty in the final values. IN 1975, Sinha[Helv.Chim.Acta 58,1978 (1975)] has introduced a linear relationship of the properties(Pj_) of the f-elements and ions by plotting the observed data as a function of the total orbital angular quantum number(L) of the originating atoms or ions in the ground state [Pi = WiL + ki], the "Inclined W" theory[Sinha, Struc- ture and Bonding 30,1 (1976)]. Here, the application of this linear relationship in calculating the sixth(lPg) and the higher IP's would be demonstrated. THE method of calculation is actually very simple. We t*>eat a given ionization energy as a single variable (Pj_) and not as a four-compoi;ent system of Sugar. The calculations are based on two simple correlations, e.g. 1. Series Correlation: for a given IP(orZIP's), the variation within each of the four tetrads(i = 1-4) is linear with the values of the L quantum numbers of the originating ions, i.e., [IP = w±h + k±] and 2, Successive Correlation: for a given lanthanide w: th fn ground electronic con- figuration, the successive IP's vary with AL, the difference between the L values of the originating and the terminating ions in question. FOR the starting point of our calculations, we have used the three sets of IP's, the IP3, IPA* IP5 of Sugag r and assumed that the ground states of the highly ionized lanthanides correspond to the 4fnn onfiguration. First, we have plotted IP-* c for the lanthanides vs. AL, and using lepst square fit we immediately obtained the sixth and some of the higher IP's for Nd,Pm,Sm,Eu,Ho,Er and . We have next used the Series Correlation and plotted the required HP's vs. L of the originating ion, to extract the IP6 for Gd,Tb,Dy,Yb,Lu and Hf. The following values, exhibiting excellent inclined W plot, have been obtained (values in eV): M5"1" Nd Pm Sm Eu Gd Tb dy Ho Er Tm Yb Lu Hf L356653C35665T IP6 78.71 81.07 81.72 82.06 83.26 85.20 86.34 84.17 85.36 85.67 87.15 87.35 38.83

RAKING use of the above two correlations, ws were able to calculate all higher IP's for the lanthanides(iP^y for Lu). Details of such calculations ar.d various corre- lations of the results would be presented and a ctritical evaluation, would be made.

—-—a Monday, July 18, 1977

OPTICALLY ACT I' Room A Room B 2 11.15 h E.O. Fischer f, ! Department of' ( O 14.00 P.Caro 3^50 Brussel; |E. Fluck 14.20 D. Attanasio „v Optica" 14.40 R. Mattes B. J.-Trzebiatowska hydride (II) he 15.00 S. Chatterjee 0. Gatteschi ding opticalTy I 15.20 S.E.C. Blum W.E. Hatfield a) by an asymme and Jacquet [Te 16.00 S.E. Livingstone B. J.-Trzebiatowska and 65°= of II, 16.20 P. Gouzerh 16.40 S.O. Wandiga D.J. Hodgson ! b) by an asymme Taddei (J.C.S. 17.00 P.A. Devillanova N.M. Karayannis I 17.20 D. Fiorani f tin compounds : 17.40 TL. Sacconi J.-F. Labarre i compound and re - E. König f -0.70° ± f}.05-

Room C Room D A benze at room tempera 14.00 Y. Murakami M. Gielen 14.20 A.L. R-ieger I. Tkatchenko (!) rea 14.40 J.C. Marchon M.M. Taqui Khan hours at room t 15.00 D.T. Sawyer B. Sarry activity is los 15.20 C.H.A. Seiter G. Dolcetti Stereos A.M. Sladkov ! stable triorgan 16.00 K.B. Yatsimirskii G. Ortaggi 3rganostannyl-t 16.20 J.I. Legg F. Pruchnik 16.40 J.J. Christensen K.P.C. Vollhardt 17.00 E.B. Paniago E. Singleton 17.20 R.B. Jordan S.C. Tripathi ta4°5nm : -«'S 17.40 N.S. Al-Niaimi A. Vaziri K.N. Mikhalevich J.V. Comassetto bi I.I 23

OPTICALLY ACTIVE TRIORGANOTIN HYDRIDES *^E CHEMIC fl. Gielen and Y. Tondeur -; j. SALLlVE . . . i:\i5TITLT D / Department of Chemistry, Free University of Brussels V.U.B., Pleinlaan, 2 - 3^50 Brussels - Belgium. "3, Bd au 69626 VIL.^ Optically active methylneophylphenyltin hydride (I) and t-butylneophylphenyltin hydride (II) have been synthesized by two different methods starting from the correspon- ding optically unstable chlorides a) by an asymmetric reduction, using the chiral hydride described by Vigneron and Jacquet [Tetrahedron 32., 939 (1976)1 yielding 55v- of I, Ul^^ : +6.13° ± 0.08° and 65'.- of II, [a]^^ : -3.74° ± 0.08n b) by an asymmetric reduction, using a method which is analogous to that described by Taddei (J.C.S. Perkin II (1973), 638) for the synthesis of optically active tetraorgano- tin compounds : conversion of the triorganotin chloride into the corresponding menthoxy compound and reduction by LiAlH, at -50°C in ether, yielding 55% of I, [a].,30—° : -0.7Oc ± t).05 and 70V, of II, [a],30° c 365nm -1.35° ± 0.07 A benzene solution of (I) looses about 50% of its optical activity after 17 days at room temperature and about 20/» after 4,5 hours at 80°C.

VI) reacts withJLiA/lD4 Jjn ether to yield the corresponding deuteride. After 18 hours at room temperature. 80% of D is incorporated and 80% of the -initial optical activity is lost. Stereoselective reactions transforming these optically active and optically stable triorganotin hydrides into optically active tetraorganotin compounds and into t^i- srganostannyl-transition metal compounds will also be described, such as

(II) -#• c-butylmethylneophylphenyl tin CJ 70° ^365nm : -°'89° ^365nm : -1'500

[I) bif1uoreny1idene> bifluorenylyimethylneophylphenyltin AIBN ,30° J : -0.70°

: +0"79°

1 ! 0 \J Kr 1.2

"-£ CHEMICAL SEriAvI-R OF C-Y1 I O'l.IC Jli.ITRûSYL COMPLEXES OF COBALT AND IRON \ ^ . TKVTHEMKO :• ,-; :•. BALL:VET Z. BILLARD and I

CATAL.VSL I.SiSTITu" DE RECHERCHES SUR LA Departm 'd, 3d au 11 novembre 191Ë Hyderah 69Ö2B VlL-cLJRo/WlE CEDEX f PRANCE 1

and ars : • i.v structural data and al.-.ost nc = ;T :: :-;scoDio dnc c-i^ioa: data are available prepare' cr poly-nitrosyl complexes whereas •"••.ononitrosyl complexes are extensively = ;._died. I~ dinitrosyl conpoun^s t^e ^itrosyl groups ^iay De non equivalent and the a^d a rapid interconversion can td-xe place (J.P. Collnan, P. Farnham and 1:2:3» 1. Dcioetti, J. Amer.Chem.Sac., _r£, 17ot i1971j]. A ccuplin" cf the nitrosyl and mol< j-igands has also been described fB.r.Lj. Johson and S. Badhuri, J. Chem. Soc. four hoi Triem. Conw., 651 (1973). We wish to : sport the chemical reactivity of

V [_ (M3;2J species [M=Fe,Coj towards strained olefins such as norbornadiene ether. (nbcO, 1.S-cyclooctadiene lcod) and vinylic compounds such as acrylonitrile analyeii ianj, styrBne (st). fCo [;»0) nba]+ Y~ , [Co(NO) cod ] +y " ( Y=PFg,BF ,C10 ) , fCoCiMO) 7 2 data. : (an)^1 PF, have been prepared at roon temperature in a quantitative yield

üj a Tiethatical reaction between LCO(IJO) _,Cl']7 and AgY in non coordinating to the 1

sc.'.vents (CH^C17, Cn._,;j0o) or i-, "eat substrate (an). The complexes behave as ; : 1 electrolytes and their infrared spectra exhibit 2 V -frequencies these ci V c, Vo) centered at 1920 - 20 and 1Ö20 - 20 cm according to the olefin. "ne reo shift observed compared to the stfarting material £Co[MO)_ClJ The com; M360 and 1790 cm ) is mainly assigned to the cationic nature of the complexes. ~~~ nomologue compounds of iron are paramagnetic and only stable in solution. Cham. G "ney lead to other nitrosyl complexes the formation df which will be discus sec.Since fMtNO^J moiety is able to coordinate olefins a catalytic activi- to ruth ty is predictable. These species are precussors for the catalytic dimeriza- coordln; tion of norbornadiene [n=Fe, Co) behave like carburations in initiating the ooordlni cationic polymerization of styrene (M=Fe, Co) and like a radical-cation CM=Fe) initiator for the polymerization of acrylonitrile. Some of these results arrange] .-jill be presented. complex'

has bee:

__. 1.3 25 ^ */ SOME NEW DlAMAGNETIC DIOXYGEN COMPLEXES OF RUTHENIUM! II) ARYliUTHIU: M« K. Taqui Shan, X. Veera Reddy and Mrs. Badar T, Khan. B. Sarry, R. Department of Chemistry Nizam College, Osmania University Institut fiir Ar Hyderabad, 500001 (A.?). India. Strafle des 17 Reaction of gi Dioxygen complexes of ruthenium(II) with mixed tertiary phosphine ether leads to and arslne ligands have been reported. These complexes were complex bourn prepared by refluxing propanolic solutions of ruthenium trichloride 1. aryl compc and the appropriate phosphine and arsine ligands in the ratio MAr (LiAi n l:2:3i respectively. The solid obtained was dissolved in benzene 2. o-arylene ( and molecular oxygen was bubbled through the solution for twenty MAr en (Li four hours. The dioxygen complexes were precipitated by petroleum 3. mixed aryl ether. These complexes have been characterized by elemental TaPhPhen2 Dipole mom en analysis, Infrared, magnetic susceptibility and electronic spectral gurated. Thou data. The dioxygen complexes obtained are diamagnetic and conform hyper fine spii to the general formula, RuCl2(PR)xlAsR}y(0g) lA), where R = Phj, this, it is of i PhgMe* HiMeg and x*y = 3« The dioxygen is irreversibly bound In pounds varies these complexes axidOto-02 was observed in the range 850-890

1 •• v 26 1.4

ARYIiLITHIUM CONTAINING TRANSITION METAL ARYL AND ARYLEN COMPLEXES .' . INTRAMOLEC 1 i B. Sarry, R. Schaffernicht, P. Veiling , r G.Den Institut fur Anorganische und Analytische Chemie der Technischen Universitat Berlin § Department Strafle des 17. Juni 135, D-1000 Berlin 12, Germany (Cosenza) Reaction of group V and group VI transition metal halides with aryl in ethyl- The c ether leads to formation of three different types of compounds, all of which contain pump is we complex bound phenyllithiumetherate: (1971) . Si linear isc 1. aryl compounds Ar = C H , C H CH ; Aren CfeH • C H CH intramolec MAr (LiAr- Et_O), la: M = V; n = 2 Ib: M = Cr, Mo; n = 3 Ic: M = Ta; n = 5 n i. o-n — — — is obtaine acetonitri 2. o-arylene compounds and the 31 MAr en (LiAr- Et O) JU N = Nb, Ta, Mo, W configurat 3. mixed aryl-arylene compounds oxidation ligands le TaPhPhen2(LiPh-Et20)3 _III_ the nitric Dipole moments in the range from 5 to 7 D show, that the complexes are cis-confi- the metal primary al gurated. Though the greater part of the substances are paramagnetic and give rise to R=CH3, C6H hyperfine split ESR spectra, most of them show NMR spectra too. With regards to (N-N), lea ( vNO 1805 this, it is of interest, that in some cases the magnetic moment of the dissolved com- type Ir(NO pounds varies with time or with temperature. Stoichiome d10IrNOL By means of partially deuterated ligands it has been possible to relate all NMR sig- 3 (1972) ) a nals to the different protons. While in the complexes_Ic_ all aryl groups are equiva- is in the lent, the compounds containing arylen groups exhibit two different kinds of aryl groups and the cc depending in the ratio 2:2, which become equivalent at higher temperature. In the case of the positions, mixed complex III lowering of the temperature causes further splitting of the different nitrosyl c It is signals of the phenyl groups, leading at last to four distinct phenyl groups in this ligands th compound. oxidazing localized Due to the low solubility of most of the substances, C-spectra have been available linear only for the complexes _Ic_. The metal bound C-atom shows resonance at very low intramolec coordinate field, quite lower than LiAr- Et_O itself. Based on these experimental observations the structure and the conversion of the compounds in solution will be discussed.

__- o/ 4 1.5 27 -.V ^ INTRAMOLECULAR REDOX REACTIONS IN METAL NITROSYL COMPLEXES. COMPLEXES G.Denti, G.Dolcetti, M.Ghedini and B.Giovannitti. A.M.Sladkq > Department of Chemistry, University of Calabria, 87030 ARCAVACATA Institute (Cosenza) Italy. Moscow. The capacity of the nitrosyl ligand to act as an electron sink or Cop^e pump is well established. (J.P.Collman et al J. Am. Chem. Soc, 9_3, 1788 (1971). Since "bent NO" donates two fewer electron to a metal than the various linear isomer does, linear bent tautomerism raises the possibility of type PhC intramolecular redox reactions. The complex Ir (NO) (CH3CN)2 (P (CbH6) ,) £ (1_) is obtained by reaction of the corresponding diiodide with AgPF6 in complex b acetonitrile suspension. The vNO (1540 cm 'KBr) stretching frequency and the 31P and lB n.m.r. data in support of a square pyramid organic £ configuration with apical bent nitrosyl and the metal in the d6Ir(III) oxidation state. The reaction of the complex 1_ with a variety of neutral trum of tii ligands leads to the formation of cationic nitrosyl complexes, in which the nitric coordination mode is changed from bent to linear and polymeric the metal oxidation state is lower of two units. In fact reactions with 1 tinction primary alcohols leads to Ir (NO) (OR) (P (C6H5) 3)2 (_2)(v(N0) 1840-1870 cm" )

R=CH3, C6H5/ C3H7). Reactions with 2,2 bypyridine or 9,10-phenantroline, possess ei (N-N), leads to the formation of Ir (NO) (N-N) (P (C H ) ) \+ (3_) complexes 6 5 3 complexes ( vNO 1805-1870 cm l). Quinones react with 1_ to give complexes of the type Ir (NO) (diolato) (P (C6H5) 3) (4_) together with phosphine oxide. sociated. Stoichiometric amount of tertiary aryl phosphine reacts with j_ to give 10 d IrNOL3 (_5) complexes (G.Dolcetti et al Inorg. Chim. Acta, S_, 531 phosphine (19"?2) ) and phosphine oxide. In the complexes 2, 3_, A_ the metal is in the dselectronic configuration, the nitrosyl is linearly bonded, of PPhj t and the complex geometry is square planar or a trigonal bipyramid quency "by depending on the ligands number. Chelating ligands occupy axial-enuatorial positions. For the d1 "complexes .5 a tetrahetral geometry and linear veakening nitrosyl coordination mode has been determined. It is noteworthy that during the reactions of 2_ with these neutral CHC bond 6 8 1 ligands the metal is reduced, d ->-d ->-d °, even if the reactant is a strong The anE oxidazing agent as a quinone, while the oxvdazed counterpart can be localized in the group, which always changes from bent to of the cd linear coordination mode. The reaction pattern proposed is an intramolecular redox reaction between the central metal and the ( PhCaCCi coordinated nitrosyl group without any assistence of the entering group. found fc

H.M.M.She 28 ^jT I.R.I

COMPLEXES OF COPPER PHEFYLACETTLIDES WITH PHOSPHINE LIGANDS A.M.31adkoy« I.R.Golding, I.A.Garbousova and V.T.Alexanyan. Institute of Organo-element Compounds, Academy of Sciences of the USSR, Moscow. Copper phenylacetylydes has been shown to be able to coordinate various number of triphenylphosphine groups to form complexes of the

type PhC=CCu(PPb.^)fl , where _n= I, 1,5. Three variations of this com- X-'' ' •'*'•'*' • complex have been isolated. They differ in their color, solubility in organic solvents, vibrational and electronic spectra. The Raman spec- trum of these compounds is markdly different from that of the original polymeric copper phenylacetylyde which indicates to an essential dis- tinction in their structure. The PhCHGCu (PPhj)^ complexes do not possess either a polymeric structure or any photoconductivity. These complexes are soluble in organic solvents where they are differently asi sociated. In benzene solutions a transition from the form vicher in phosphine to the poorer one is observed. The addition of one molecule

of PPh^ to the PhC=CCu molecule leads to an increase in ">CaC fre- quency by 92 cm"" (1926 -»20l8cm"'). The latter can be explained by the veakening of 3 - and ^^interactions between the copper atom and the CHC bond cyg the ethynyl group.

The analysis of the spectra in \£c region shows that the structure of the complex can be representing as consisting of two fragments:

( PhC5CCxiC=CPh )~"and Cu(PPh3)n (n= 2,3 ). A similar structure was

found for the complexes PhCsCM PMe3 (M=Ag, Cu) (P.W.R.Corfield, H.M.M.Sherer , Acta Cryst., 21, 957 (1966) ).

r IM*1MfeU the substrate will be discussed.

1.6 29

THE CATALYSIS OP Pd(II) COMPLEXES OU THE REACTIVITY 0? ALCOHOLS C'/ A NEW \ E.L'incione, G.Ortaggi and A.(Sirna y/ FiPruçï Centri CM dei lieccanismi di Reazione, e delle Sostanae Organ!ehe / Institt Naturali, c/o Istituto ii Chimica Organica, Univa roita di Roma, 50-383 The reactj ooi00 fioma, Italy. mines yiel talysts aj metal /Zul The alcohols were found to indergo a novel reaction catalyzed by sent studj (PhClO.PdCls complex, i*e. the competitive elimination and substitution nol under by chloride ion of the alcoholic group (E,Y.incione, G-.Ortaggi and A. stable con Sirna, submitted for publication), the solutJ Cholestanol and epicholestanol, warmed at 50° for two Hours tion becon cipitate s in benzene solution in the presence of (PhCN)«PdCl produced t alcohols s a

N" ' A NEW VERY ACTIVE CATALYST FOR HOMOGENEOUS HYDROGSNATION <•"" •' F^Pruciinik, M.Zuber, S.Krzysztofik / Institute of Chemistry, University of Wrociaw, Joliot-Curie 14, 50-383 Wroclaw, POLAND The reaction between RhoC^/CgH^. /^ and 1,3-diaminooropane or other dia- mines yields catalysts whose activities exceed that RhCl/PPh,/,.These ca- talysts are, however, unstable; during the reaction is reduced to metal /Zuber M.,Pruchnik F.,React.Kin.Cat.Lett.,4 /1976/ 281/.In our pre- sent studies the reaction_of RhpClp/CgH,.^/^ with 2-aminopyridine in etha- nol under hydrogen at a molar ratio Rh:amine=1:1 was found to yield more stable compounds of much higher catalytic activities.Daring the reaction the solution changes colour from light yellow to yellow brown.The solu- tion becomes brighter after adding the olefin.After several hours a pre- cipitate soluble in very polar solvents is formed /DMSO, DMFJHCONHJ,/.Other alcohols also may be used as solvents.The highest is the hydrogenation rate of alkenes-1, then cycloolefins, the slowest is the hydrogenation rate of olef ins with double bonds inside of the branched chain /'.'"'able/. Table_. Hydrogenation rates jcc/min] of some organic compounds in the system RhpClp/CgH., /^ + 2-aminopyridine + ethanol hexene-1 37 hexene-2 8 heptene-1 41 heptene-3 /cis+trans/ 28 heptyne-3 29 octene-1 40 cyclooctene 5 cis,cis-cyclooctadiene-1,5 14 di-iso-butylene 4 decene-1 28 cyclohexene 29 ; [lig.] =1,78«10~4M/l; |org.comp.] =0.67 M/l; temp.- 30°C; volume of solution = 22 ccj ^ = patm# - P vapour The catalytic activity of the system decreases at molar ratios amine:Rh higher than unity.Traces of oxygen during the preparation of the cata- lyst result in its inactivation.The activity of this catalytic system is several times higher than that of the Wilkinson complex RhCl/PPh,/, and somewhat higher than that of RuHCl/PPh,/-z.Very active systems also are formed when derivatives of 2-aminopyridine, such as 2-amino-3-methyl- pyridine, 2-amino-5-methylpyridine, are applied^ We have also shown that metal ions rearrange me ULUCI.=U K^ — S -*• - in DNA-protein complexes such as Chose that compose the chromatln of the cell nucleus. ^^ apparent that the changes induced in the structure of the nucleic acids by complexity metal ions car, influence the function of these molecules in genetic information transFpr.

,. / <- ,c 1.8 31 r COBALT COMPLEXES IN ACETYLENE CYCLIZATIONS k SIMPLE ROU R. L. Funk, R. L, Hillard III. A. Naiman, P. Perkins, S K.P.C. Vollhardt T.V. Ashwort Department of Chemistry, University of California, Berkeley, Ca. 94720 National Che USA P.O. Box 395 S n -Cycl6pentadienylcobalt dicarbonyl efficiently catalyzes the The salts [C

cooligomerization of a,to-diynes with monoacetylenes to give a varietv [CgH]2RuCl2] of bicyclic and tricyclic organic molecules containing benzene rings. only route y Similarly, nitriles can be cotrimerized to give isoquinoline derivative; representati and more complex heterocycles. Mechanistic considerations imply salts [Ru(NH the intermediacy of bicyclic cobalt (III) metallocycles capable of zwitterionic differentiation between acetylenes and nitriles. The photochemistry complex of s of the catalyst results in di- and trinuclear cobalt clusters of determined c improved catalytic efficiency. A tetranuclear cluster of reduced The salt (II catalytic potential has also been obtained. Polymer supported reactive rut 5 n -CpCo(C0)2 allows the thermal and photolytic generation of reactive ligands. I intermediates. Scope, limitations and mechanisms will be discussed. the purple f heterolytic 705 (1976) £ ligands (II] shown to be + [RuHL5] t I alcohols ha\ dioxygen, tl (T.V. Ashwoi dithiocarbai The implical involving C( pp. 344 and

Other react] given the ti the neutral

The effects these produ< 32 1.9

> \ SIMPLE ROUTE TO NEUTRAL AND CATIONIC SYSTEMS OF RUTHENIUM (II) y T.V. Ashworth, R.H. Reimann and E. Singleton National Chemical Research Laboratory, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria, 0001, Republic of South Africa.

The salts [CgH12Ru(N2H4)4](BPh4)2 (I) and [CgH,2RuH(NH2NMe2)3]PF6 (II), prepared from [CgH.-RuCl.] (x>2) in high yield are highly labile in solution and have provided the only route yet reported to a wide range of new ruthenium (II) systems. For (I) representation reactions in acetone have produced the first amine-bonded hydrazone salts [Ru^HjNCMe-KL, ] (BPh, )„ with small phosphites or phosphinites, the arene-bonded zwitterionic species [n -C^H.BPh RuH L_] with bulky ligands and a highly insoluble complex of stoicheiometry C.H.^ BPh, the structure of which is at present being determined crystallographically.

The salt (II) is, however, the more versatile of the two products forming a series of reactive ruthenium (II) hydrido-cations with mono- and bidentate tertiary phosphorus

ligands. For example with the chelating ligands L2 (L2 = Ph2P(CH2) PPh2; n = 2-4)

the purple five-coordinate salts [RuH(L_)?]PF, have been isolated and shown to effect heterolytic fission of dihydrogen (T.V. Ashworth and E. Singleton, Chem. Commun., 705 (1976) and mono-arylacetylenes under ambient conditions. With monodentate

ligands (II) produced the series [RuHL 1PF, of which [RuH(PMeoPh)C]PF. (Ill) has been shown to be the most reactive because of the sterically-assisted dissociation process [RuHL ] Z [RuHL ] + L occurring in solution. Reactions of (III) to date in alcohols have included the formation of the carboxylates [Ru(0 CR)(PMe.Ph) ]PF, with L Z H D

dioxygen, the monoalkylcarbonates [Ru(0 COR)(PMe2Ph) ]PF (IV) with (T.V. Ashworth and E. Singleton, Chem. Commun., 204 (1976)) and the carbamato and

dithiocarbamato complexes [Ru(X2CNMe2) (PMe^h^jPFg (v) (X = 0,S) with CX and HNMe . The implications of the formation of (IV) and (V) to some catalytic reactions

involving C02 (M.E. Volpin and I.S. Kolomnikov, Organometallic Reactions, Vol. 5 (1975) pp. 344 and 347) will be discussed.

Other reactions of (II) with L (L = PMe2Ph and PMePtu) and HO, H S, HSR or H0R have

given the triply-bridged salts [Ru2X L,]PF (X = OH, SH, SR, H) and with LiX (X = Cl.Br)

the neutral product [(CgH]2RuHX)2NH2NMe2].

The effects of ligand size and metal hydride basicity on the reactivity of some of these products formed will be discussed. that compi usua!

y 1.10 33 HALOGEN DERIVATIVES OF MIXED AMINE TUNGSTEN TRICARBONYLS RiACTl S.C. Tripathi, S.C. Srivastava and C.P. Singh Ali 7a Depart] Department of Chemistry, University of Gorakhpur, Gorakhpur - 273001, INDIA I si" an a: Pnenyli A variety of neutral, anionic and cationic halometal pnarmai •as a s carbonyls displaying uncommon oxidation states, geometries and ? T • , Zl m J. ..A magnetic properties, have been reported by controlled oxidation and ^.. of substituted metal carbonyls. From the literature survey it M^ 3): appears that considerable attention has not been paid to the as an i noticec halogenation of mixed Iigand derivatives. Joacer-9 We have studied the bromination and iodination of some aosorpt

T I .... mixed ligand tungsten tricarbonyIs , W(CO)~ (L-L)L' (L-L»o-phen or '- • J • jJU intexac 2,2'-bipy; L1 • amine molecule), at room temperature under 1<. - . Ac nitrogen atmosphere and isolated the products W(CO),(L-L)L'lj utilize and W(C0).(L-L) L'Br^. Therefc coacerv The IP spectra of these derivatives exhibited three betweer strong CO bands in the region 2042-1880 cm , the bands of tiie sys brominated derivatives being slightly higher. Other bands that preriou (1975)) appeared in the spectra were invariably present in the parent agsnt i derivatives. ol aiaci Expulsion of amine molecules even after drying the conside which b complexes up to 37oc/lmm pressure was not observed. The tr:s ant complexes show anomalous conductivity behaviour in different tiaat ?ik: solvents. work. solutio tragaca PIN was theory occurin, in the donor and acceptor are relatively close one co anotner. From a more general point of view it becomes obvious that it may be regretted that the use of the name "Charge transfer complexes" be practically restricted to compounds which hardly deserve to be called complexes and whose formation does not usually correspond to a significant charge transfer.

34 1.11

REACTION Cf P Ali Vaziri. Department of P ,cnooi •- i Pnarmacy, University of Isfanan, I&fanan, Iran. Kaenylmercurie nitrate iu.1 , an oi'iicial Organmetalic Compound for pnarmaceutical preparations, nas oeen us:d as a, preservative. P*.N nas a slow but relatively effective sterilizing effect u.« Klein, ...ellwood, and :harm. Pnarmacol, o, 725,(1954) and U.A. Kohn. , x . Jer-snenj/eld, ana .,. r,arr, t. Fharm. bci., $d, 967 ( 1-^ 5)). '.Vhen using Gaioanum, tne jum resin of Ferula gumosa Boiss, as an ingredient ol coacervate sy^tai.s its anti-microDial effect was noticed anu reported (.i. /uz^i, Flanta ...edica 2c, 370, (1975)). Joacarvate syotems r.?.ve oein su ^esxed as models for the study of absorption and distrioution cii.-:r act eristics ol drugs (H.G. Booiji and !.J. ijundenburg de Jcnj 'TrotcplasrnatolOoia, Siocolloids and their interactions". Sprin^er-Vei-lag, Austria (195-J) and G.N. Ling, Ann. 1T._. Acad. oci., 1^5, 401 (I9o-;J). iae purpose of this study was to utilize drug partitioning of ?l.':'. -_n complex coacervate systems. Therefore, PkK was incorporated into different coacervate and non- coacervate systems. After iiaving allov/ed partitioning to occur between coacervate and tnc- equiiiDri-um phase, inhibitory effect of tiae system on the growth of a micro-organism was evaluated by a previously published technique (A. Vaziri, Planta kedica, 28, 370, (1975)). iM alone •••as consistently an effective anti-bacterial a^ent in 0.^04% and 0.002.. concentrations. _n the presence of samples ol macromolecules examined its anti-microbial effect was either considerably reduced or completely lost, riven in the case of galoanut which has an anti-bacterial effect by itself,when combined with P&N trjs anti-microDial effect .vao diminished. It might be anticipated that HsLN might react with natural macromolecules examine'd in this work. To examine this, the reduced viscosity of dilute aqueous solutions of the ingredients of tne systems examined (accacia, gelatin, tragacanth and galbanum) as well as their mixtures with and without ?J.K was measured. Based on viscosity measurements and folding chain theory of polyelectrolytes in solutions, the possibility of reactions occuring between macromolecules themselves as well as those with BL\ have been IO.I1 OJ..W OX.IC

MAKING use of th<* above two correlations, we were able to calculate all higher Ir's for the lanthanides(lP]7 for Lu). Details of such calculations ar.d various corre- lations of the results would be presented and a ctritioal evaluation would te made.

/ •

I.R.2 35

JLEFINATION REACTIONS WITH PHENYLSELENOPHOSPHORANES AND PHOSPHONATES.

N, Petragnani and J. V. Comassetc

Instituto de Quimicp. da Univeraidade de Sao Paulc - USP Departamento as Qumica da Universidade de Sao Carlos

We have recently reported that the reaction of lphenylseleno)methylene-and (phenylseleno)ethylide>.e-triphenylphosphoranes with aldehydes give vinylic selenides in good yields (J. Organometal. Chem, U£, 281(1976). p'run a ,P=CRSei> • • •> R'HC=CRSe +

_ r , .„- HAW, n-BuL^ t>SeBr ^ n_^_,_. £_> mc=CHSe$ The Z isomer was obtained as the main product by addition of SeH R-C=C-R RHC=CHSe Ketones fail to give Wittig type products with selenophosphonates carbanions, probably due to proton exchange. CH2RCOR' r (EtO)2P(O)CRSe<\> (EtO)sP(O)CHRSe CHR=C-R' The vinylic selenides are hydroliticaly cleaved with either HgCljCHSCN or with CFJCOOH to afford high yields of the corresponding ketones. o ]

,LLk A f 36 II.1

-/CHARACTERIZATION OF VITAMIN B12 FUNCTIONS BY MODEL SYSTEMS CATALYSIS Yukito Murakami , Yasuhiro Aoyama, and Shigenori Nakanishi THE HERBIC Department of Organic Synthesis, Faculty of Engineering, Kyushu University, J. 0. Edwa Fukuoka 812, Japan Department Providence Despite many studies on the chemical behaviors of vitamin Bj2 coenzyme, the reason why the oorrinoid moiety is indispensable for the development of catalytic functions and Methyl vio other N^-macroayclic analogs can not be substituted for it has not been clarified yet. [A. A. Akh As an elaborated approach to this problem, the structural and kinetic characterization a redox in of the cobalt complexes of bis- and tetradehydrocorrins has been performed. A. Ledwith It has now of magnesi

V H,C C2H5

BDHC TDHC

The TDHC complex (JJ has shown the following unique properties and is far from analo- gous to the cobalt corrinoid {})'• (i) JL CCo(II); X, none; Y, CIO/] is readily reduced When the i even with unsolvated OH" to the Co(I) species; (ii) ^.[Co(III); X, CN"; Y, none] is a highly efficient catalyst for thiol autoxidation; (iii) ^[Co(III); X, CN"; Y, none] 5 * 10~4 A shows an intense charge transfer band associated with the Co-CN bond in a longer wave- to an app length region. The powerful oxidation ability of Co-TDHC is consistent with its ex- decrease i ceptional Co(II)-Co(I) redox potential (-0.26 V vs SCE in methanol by cyclic voltam- catalysed metry) which is appreciably positive relative to those of analogous cobalt complexes. of magnesi Lack of nucleophilicity of Co(I)-TDHC toward alkyl donors is understood on this basis. is first- The BDHC complex {2} was found to be quite similar to the cobalt corrinoid in its be- been obse havior: reduced to the Co(I) species which gives the Co-alkyl derivatives upon treat- At p ment with appropriate alkyl donors; and electronic spectra of various derivatives [Co- MgTPP and (III) with X=CN~, Co(I), and Co(III)-alkyl] quite similar to those of the correspond- indicate i ing corrinoid complexes. The effective nucieophilic reactivity of Co(I)-BDHC is re- low pH. flected on its reduction potential. The reduction potential ofJMs more negative than raised im that of_3_by at least 0.6 V, where cobalt is in +3 valency state and X is CN". Various reactions of the BDHC complex with substituted alkanes have been carried out.

in flWihV* J +0-79°

II.2 37 I'

CATALYSIS OF MAGNESIUM REMOVAL FROM MAGNESIUM TETRAPHENYLPORPHYRIN BY 0 / OIHALOTITANII THE HERBICIDE METHYL VIOLOGEN J. 0. Edwards, G. Levey, A. L. Rieger, and M. A. Silverman Department of Chemistry, Brown University Providence, Rhode Island 02912, U. S. A.

Methyl viologen (MV ), also known as "Paraquat", is a herbicide (A. A. Akhavein and D. L. Linscott, Residue Rev., 2_3, 97 (1968)], a redox indicator, and a source of cation radicals [A. J. Bard, Attet A. Ledwith, and II. J. Shine, Adv. Phys. Ova. Ckem. , jL_3, 155 (1976)]. 2+ complexes of It has now been shown that MV is also a catalyst for the release dation state: of magnesium from magnesium tetraphenylporphyrin (MgTPP). rin H2P in' of oxygen an< porphyrin coi We n< complexes of

H2TPP = tetn of titanium-1 sorption spei configuratioi discussed. When the initial MgTPP concentration is 4 * 10~ M, the half-life of 2+ Desp magnesium extrusion is decreased from 23 hours to 1.4 hours by MV , — 4 of water, dil 5 * 10 M in methanol, buffered with tris(hydroxymethy 1)aminomethane ponding titai to an apparent pH 5.7. The reaction is followed by observing the also be effei decrease in the Soret band of the metalloporphyrin. For the -4 -1 Prel catalysed reaction at pH 5.7, 25°C, h fcg = 1.4 » 10 s . The rate phyrins with of magnesium loss is pH dependent in the apparent pH range 5-9 and will be presi is first-order in MgTPP. In this pH range, no new uv bands have been observed on mixing MV with MgTPP. At pH 2, a green solution is formed immediately on mixing 2+ MgTPP and MV solutions. A new band appears at 437 nm which may indicate interaction between the central magnesium ion and MV at low pH. The original spectrum of MgTPP is seen again if the pH is raised immediately. has bee:

38 II.3

OIHALOTITANIUM (IV) PORPHYRINS : PRECURSORS TO LOW-VALENT TITANIUM PORPHYRINS •(II, AND TO DIOXYGEN COMPLEXES. OXYGEN EVOLU1: Jean-Marc Latour, Jean-Claude Marchon, Masayuki Nakajima Donald T. Sail Departement de recherche fondamentale (EOA) Department oj Centre d1etudes nucleaires de Grenoble California 9: 38041 Grenoble (France) Manganese coi bipyridyl (b: Attempts to effect the reduction of dioxygen and dinitrogen by porphyrin oxidation-re< complexes of titanium has long been frustrated by the inability to get low oxi- manganese gr< dation states for Ti in these compounds. Insertion of Ti into a free ba>o porphy- redox chemis IV rin HgP invariably leads to a titanyl complex PTi 0 when rigorous exclusion and controlli of oxygen and/or moisture is not achieved. Previous studies have shown that titanyl epr, and mag] porphyrin complexes are highly stable and cannot be reduced on the metal. characterize We now present the successful isolation and characterization of dihalo- complexes. IV complexes of titanium (IV) tetraphenylporphyrins TPPTi X, (X = F, Cl, Br; hydrogen peri III HgTPP = tetraphenylporphyrin), and their easy reduction to TPPTi X. The presence and mechanisi of titanium-halogen bonds in these complexes is apparent in the far infrared ab- chemical, spi sorption spectra (Ti-F : 647 cm"1; Ti-Cl : 358 cm; Ti-Br : 280 cm" ). Their manganese(II configuration in solution, as deduced from high resolution NMR studies, will be reversible o: discussed. sufficiently Despite their low solubility and ready hydrolysis to PTiIV 0 by traces of water, dihalotitanium (IV) tetraphenylporphyrins can be reduced to the corres- ponding titanium (III) complexes by chromium (II) compounds. This reduction can also be effected electrochemically. Preliminary results concerning the reactions of halotitanium (III) por- phyrins with molecular oxygen, and the formation of dioxygen adducts therefrom, will be presented and discussed. has been predicted to be more stable than an edge-on arrangement.

II.4 39

MANGANESE(II,III,IV) POLYIMINE COMPLEXES AS MODELS FOR THE PHOTOSYNTHETIC k ELECTRON TRj OXYGEN EVOLUTION REACTION Donald T. Sawyer and Mark M. Morrison V C.H.A. Seiti Department of Chemistry, University of California, Riverside, {" Department < California 92502, U.S.A. 3" Los Angeles Manganese complexes formed by 1,10-phenanthroline (phen), 2,2'- Resonai bipyridyl (bipy) and related polyimine ligands in aprotic media undergo provide inf< Oo to water oxidation-reduction chemistry which may parallel the behavior of the about the h< manganese group in photosystem-II of green-plant photosynthesis. The charge-stat< environment redox chemistry of the complexes has been studied by cyclic voltammetry enzyme in ai and controlled potential electrolysis. UV-visible spectrophotometry, epr, and magnetic susceptibility measurements have been used to characterize the solution chemistry, formulas, and structures of the complexes. The reactivity of the various complexes with oxygen, hydrogen , hydroxide ion, and catechol has been determined, and mechanisms are proposed that are consistent with the electro- chemical, spectroscopic, and kinetic data. Di-u-oxo bridged binuclear manganese(III,IV) and (IV,IV) polyimine complexes undergo successive reversible one-electron reductions and oxidations at potentials sufficiently positive to oxidize hydroxide ion and other substrates. compounds in solution will be discussed.

40 II.5

ELECTRON TRANSFER REACTIONS IN CYTOCHROME OXIDASE 0 *REACTIVIT

C.H.A. Setter, R.A. PerreauU, S.G. Angelos, and R. Margalit K.B. Yats Department of Chemistry; University of Southern California •*/. Los Angeles, California 90007; U.S.A. Institute Resonance Raman and electron paramagnetic resonance (EPR) spectra are used to Kiev, U provide information about the sequence of events in the four electron reduction of 0? to water by cytochrome oxidase. In particular, the change in enzyme conformation about the heme and copper components of oxidase is established from spin-state and charge-state sensitive resonance Raman bands during electron transfer. The ligand Histidin environment of these metal centers is further explored by EPR spectroscopy on the enzyme in an oriented bilayer matrix. oxygen ar transfer orbital ( reactivit place wit reduced t histidinc

CoHist, £ of two ei

Some redi acid etc] compound! catalytii

Molecula: of cobal II.6 41

. REACTIVITY OF DIOXYGEN COORDINATED BY AMINOACID COBALT (II) COMPLEXES / 2* SUBSTITUTION K.B. Yatsimirskii, Yu.I. Bratushko, I.L. Satsny. J. ivan o Institute of Physical Chemistry, the Ukr.SSR Academy of Sciences, Department o Kiev, USSR. Pullman, Was The uniquely opportunity : as those pro I Histidin complexes of cobalt(II) (CoHist-) reversibly binds molecular en.-'"me svstei oxygen and forms the compound Co Hist.0 . As a result of partial Zm M), Mn(i: 2 2 and Ru(II) ei transfer electronic density from cobalt atoms onto antibonding dioxygen ber of studie orbital (Jj,* ) coordinated molecular oxygen has a rather high ions to stud) results of OL reactivity. Homolytic fission of this coumpound is suggested to take Modify enzyme place with formation CoHist20 type particles. These particles are Study the rol found that Co reduced by two electron reducing agents (sulphite, manganous chelating age histidinate) according to scheme: enzyme residu peptides whos CoHist20 Red -* CoHist- RedO metalloprotei graded in ord which are bei CoHist- again binds Q~and in such a way oxidation catalytic process ing residues. of two electron reducing agents by 0- can be realised. glucose toler glucose Tnetab very difficul Some reducing agents (coordination compounds of cobalt (II) ascorbic and chemical ch.iracterizat acid etc) reduce Co2Hist402 (CoHist20) with formation of cobalt (III)

compounds (CoHist2OH). Thus activation of 0_ can be observed but catalytic process is not realised.

Molecular oxygen can be also activated by mixed coordination compounds of cobalt (II) with aminoacids and imidozole. 42 II.7

SUBSTITUTION-INERT METAL IONS AS PROBES OF BIOLOGICAL FUNCTION

J• Ivan Legg, Michael S. Urdea, Brian D. Warner and Thomas J. Wierenga

Department of Chemistry and Biochemistry Program, Washington State University, Pullman, Washington 99164, U.S.A.

The uniquely characteristic probe capabilities of metal ions have afforded an excellent opportunity for an interdisciplinary approach to the study of metalloproteins, as well as those proteins not possessing metal ions as a co-factor. Until recently the metal- en:'"r.ie systems studied have involved primarily substitution-labile metal ions (e.g., Zni'!), Mn(II), and Co(II)). Substitution-inert metal ions such as Cr(III), Co(III), and Ru(II) exhibit well established "stop action" characteristics, and recently a num- ber of studies have appeared which have employed the kinetic inertness of certain metal ions to study p^otein_^t,r_ucj:_urje-function relationships. This paper will present the results of our investigation into the'use of substitution-inert metal ions to: (1) Modify enzyme amino acid residues. (2) Determine ligating residues in proteins. (3) Study the role of Cr(III) in glucose tolerance. In the first of these studies we have found that Co(III) will bind to an enzyme residue which has been modified to form a chelating agent. Such a metal ion mcdlfication can be used to establish whether an enzyme residue is essential to catalysis. In the second study we are constructing small peptides whose amino acid composition resembles that of metal ion binding sites in metalloproteins. Cobalt(III) complexes of these peptides will be proteolytically de- graded in order to establish the viability of corresponding Co(III) protein complexes which are being degraded in an attempt to isolate fragments containing the metal bind- ing residues. In the last mentioned study we are constructing Co(III) analogues of the glucose tolerance factor (GTF) which appears to be a small Cr(III) complex involved in glucose metabolism, possibly through interaction with insulin. Thus far GTF has proved very difficult to characterize, and it is our anticipation that the Co(III) (a spectral and chemical analogue of Cr(III)) complexes we are studying will facilitate characterization of GTF as well as possibly show GTF activity. formed wb pyridine,

II.8 43 4/ THE MACROCYCLIC EFFECT EXHIBITED BY CYCLIC POLYETHER LIGANDS PROTONATIOI

J.J. Christensen, R.M. Izatt and J.D. Lamb M.H.M.F. C; Departments of Chemical Engineering and Chemistry and Thermochemical Institute, Departamentc Brigham Young University, Provo, Utah 84602 U.S.A. N,N'-digly< The term "Macrocyclic Effect" has been coined O.K. Cabbiness and O.W. Margerum, tons in th< J.Am.Chem.Soc. 9l_, 6540 (1969)) to describe the greater stability observed for complex (Ni the complexes of cyclic ligands over those of open-chain ligands of similar The rate 0" structure. This enhancement in complexing power of cyclic ligands over the linear counterparts seems to be of universal application. We and others have be much sl( likewise shown that the cyclic polyethers form much more stable complexes than of other a< corresponding open-chain polyethers. It is well established that the chelate reactions < effect, of which the macrocyclic effect is essentially an extrapolation, is order in tl of entropic origin. However, a certain amount of controversy has arisen over constant (I the specific origin of the macrocyclic effect, whether it be the result of more favorable enthalpy (F.P. Hinz and D.W. Margerum, Inorg. Chem. U, 2941 (1974)) or entropy (L. Fabbrizzi, P. Paoletti and A.B.P. Lever, Inorg. Chem. 1J>, 1502 The proton* (1976)) terms in the cyclic ligand reactions. In order to better understand the origin of the macrocyclic effect we have studied the reaction of cyclic above pH6 v and open-chain polyethers in methanolic solutions. There are distinct advantages reversi bi1• in studying the macrocyclic effect using cyclic polyethers. (1) The ligands reaction k- are uncharged at neutral pH and their complexing ability is not pH dependent, spectrophoi (2) the metal ions which form complexes with these ligands, namely the alkali means of a and alkaline earths, can be considered to be simple charged bodies, (3) the size of log K is manageably small. The rate cc In each case the stability of the cyclic polyether complex was found to ral mecham far surpass that of the complex formed by the linear ligand. However, our data oligopepti c reveal no trends in AH or AS among the cations studied to explain the macrocyclic Table I. Gc effect. The sodium complex seems very much stabilized by the entropy term, with little enthalpy contribution. Stabilization of the complex on Acid the other hand is due totally to the enthalpy contribution. And the H 0+ complex is stabilized by both enthalpy and entropy, although the enthalpy term 3 predominated. These results tend to show that the source of the macrocyclic Malei + effect is not simply defined and that different systems may be responding to H (G1 different stabilizing factors. Chore From our findings to date we have been unable to reach specific conclusions Formi as to the exact origin of the macrocyclic effect. The ligand solvation enthalpy Aceti approach does not seem to correspond to all the experimental observations. In Malon some cases the macrocyclic effect is almost entirely enthalpy driven. In other instances, however, only entropy or a combination of enthalpy and entropy seem H2EDT to be important. A comprehensive examination of these various effects for the H?0 systems studies will be presented. aNiH somewnax nigner man i-nai- ux nunui/rruy yvc^ <=*.- *., formed when derivatives of 2-aminopyridine, such as 2-amino-3-methy1- pyridine, 2-amino-5-methylpyridine, are applied»

44 II.9 I PROTONATION REACTION OF N ,N'-DIGLYCILETHYLENEDIAMINENICKEL(11) STUDIES OF

M.H.M.F. Cardoso and E.B. Paniago COMPLEX OF

Departamento de QuTmica, Universidade Federal de Minas Gerais, Bel o Horizonte, BRAZIL. B. Erno an Department N,N'-diglyci1 ethylenediami ne (DGen) is known to ionize its two amide pr£ The optica tons in the formation of a yellow, diamagnetic, square-planar nickel(II )

complex (NiH_?DGen) (K.S.Bai and A.E.Martell, J.Am.Chem.Soc.91, 4412 (1969)). triazacycl The rate of the H,0 reaction with this Ni(II) complex has been found to chromatogr be much slower than normal, diffusion-controled reactions. In the reaction J. Am. Che of other acids with the complex a general-acid mechanism is observed.The reactions are first order in the concentrations of the acids and first reacts wit order in the concentration of the complex. A solvent dissociation rate a rather i constant (k.) is also included in the rate expression: crystalliz + rate = (kd + kH jH30 j + kHXJHX;) |NiH2DGen| salt is so The protonation is followed by dissociation of the complex. The reactions above pH6 were run in the presence of EDTA, as a scavenger, to avoid can be obt

reversibility. Several acids were used as buffers in the measurement of the yield (-)5 reaction kinetics. The faster rates were followed on a stopped-flow racemic Ni spectrophotometer and the slower ones either spectrophotometricaly or by means of a pH-Stat, containing The rate constants for the acids tested (Table I) , are shown to fit a gene- isomer is ral mechanism for the proton transfer of a simi 1ar reaction with nickei(II)- Stopped-fl oligopeptide complexes. a NiTRI(OH2) Table I. General Acid Rate Constant for the Reaction of NiH_2DGen wi th Acids isomer use Acid pKa

+ solubility H30 -1.74 (6 :2)xlO° Maleic 1 .80 (1.0 ±.3)xlO' for the Ni H+(Glycine) 2.47 (1 .2 2.4)xl0' It was als Choroaceti c 2.70 (1 2 ±.2)xlO' ligand sue Formi c 3.65 1 .6 *.7)xl0 Acetic 4.65 4.9 -.5 J. Am. Che 5.40 4.80 -.09 Maloni c of NiTRI(0 H2EDTA 6.24 0.5 --. 1 -5 13.8 1 .1x10 methyl est self-consi i -4M, 25,0 b, 0,1 M NaCIO, NiH_20Gen = 3.5x10 and its de these produc

/ 11.10 45 / NICOTINE A STUDIES OF THE REACTIONS OF HISTIDINE DERIVATIVES WITH A TRIDENDATE SCHIFF BASE "c j-Numan S. A COMPLEX OF NICKEL(II), Ni

isomer used. Therefore the resolutions described above result in differing complexes

solubility and adsorption properties rather than differing formation constants

for the NiTRI - histidine complexes.

It was also of interest to determine the sequence of events when a multidendate

ligand such as histidine complexes with a metal ion (J.E. Letter, and R.B. Jordan,

J. Am. Chem. Soc, 97_, 2381 (1975)). Therefore the kinetics of the reactions 2+ of NiTRI(OH.)3 with histidine, 1- and 3-methylhistdine, histamine, histidine

methyl , hercynine and imidazole were studied. The results lead to a self-consistent set of reaction paths for the complexation reactions of histidine and its derivatives. these products formed will be discussed.

46 11.11

/" NICOTINE ADDUCTS OF COPPER(II) AND NICKEL(II) CHELATES

V

n- Department of Chemistry, University of Baghdad, Adhamiyah, Baghdad, Iraq.

Bis(thenoyltrifluoroacetonato)copper(II) , CuCtta),, forms 1:1 adduct with nicotine Nic, Pyridine, Py, and N-methylpyrrolidine, NMP. Thermodynamic date of adduct for- mation, determined spectrophotometrically in benzene, are almost independent of the base. (-£G°) and (-&H°) at 30°C are: Py 17.8, 26.0; NMP 18.1, 27.0; Nic 18.2 28.0;kJmol . Also while pyridine N-oxide, P0, and N-methylpyrrolidine N-oxide NMPO, form adducts that are much less stable than those formed with their respective bases, the nicotine N-oxide adduct is as strong as the nicotine adduct. (-*^G°) and (-AH0) are: PO 13.1, 21.0; NMPO 16.0; 22.0; NicO 18.1, 26.0 kJmol"1.

Both diacetylbisbenzoylhydrazonenickel(II), NiD, and bis(monothiothenoyltrifluoro acetonato)nickel(II), Ni(tta)-, form 2:1 adducts with Nic, Py and NMP. The thermo- dynamic of adduct formation in benzene reveal that the data of the pyridine adduct are very close to those of the nicotine adduct in both systems, while the data of the NMP adduct with each nickel chelate show a remarkable decrease in its stability 0 0 in comparison with the Nic and Py adducts. (-&G ) and (-&H ) are: NiD(Py)?

21.0, 57.4; NiD(NMP)2, 10.7, 50.7; NiD(Nic)2 22.7, 54.6; Ni(ttta)2(Py)2 32.2, 46.0;

1 Ni(ttta)2(NMP)2 19.5, 46.0; and Ni(ttta)2(Nic)2 35.3, 50.0 kJinol" .

These results and the observation that 2-phenyl N-methylpyrrolidit^e does not react with any of these metal chelates indicate that nicotine coordinates in these metal complexes through the nitrogen atom of the pyridine ring. PJ.K was theory < occurin; Dai

II.R.I 47

£ (> COORDINATION VANADIUM (II,HI,17) GROUND s: 1 J - £• V.V.Dovgei, A.N.Sergeyeva, K.N.Mikhalevich DOWN TO ( v *\ ?" Polytechnical Institute. P.O.Box 290646, Lvov, USSR P. Caro, Laborato Information on vanadium cyanide complexes is rather scarce*Only Meudon I recently it was reported heptacyanovanadate (B.G*Bennet,D,Nicholls,

J*Chem.Soc*9, 1204(1971). We have obtained. K^ V(CN)6 . 5H2O(I), The and withou K4 V(CN)o 2H20(II), K, VO(CN)c (III) in a crystaline state. Results of magnetic sensitivity in ^EEe range of 70 - 200 K point are couple out the independence of vanadium cyanide complexes effective magnetic components moments on temperature, and the uncoupled state of their d-electrons. electrosta 4 EPR-spectroscopy has proved that the exchange of two cyano-groups F . the s on water molecules is occuring successively in an aqueous solutions meter ^ , formalism, for VO (CN)5 3". As a result to derivatographical studies it has been found out applied oti that in spite of existing same common of stages of thermal dissocia- of the mat tion complexes their thermolysis processes ar« taking place to their The individual graphs. The final products of decomposition at 900°C are the d cot vanadium , potassium cyanide, nitrogen, dicyanogen. to 400 cm Vanadium nitrides have not been found in a solid phase* to 80000 t Studies of activation activity of coordination vanadium cyanieLas 80000 cm" (II), (III), (IV) at low-temperature in emulsion redoxpolymerization of BQ and of unsaturated hydrocarbons (V.A.Puchin, A.N.Sergeyeva et al,Scienti- Ben fic Briefs. Chemical Industry, "Higher school", K,1974,p*50) allowed terized b; to reveal that the synthesized compounds are effective activators at 6 meet. E. 10-20°C, ensuring high rate and degree of polymerization* of the gn Compounds (I) and (II) are active reducing agents, so be comput JS° V(CN)f-^/ V(CN),, **" = -0,S6i> v. for any m Coordination vanadium cyanides complexes activity change pro- the very portionally to their oxidation-reduction potentials. with a va 4 According to obtained polymerization constants promoting action also B 0. of solts decreases in the following succession: results t *- VO(CN), *~. between n ^ and galbaaum) as .ell as their mixtures with and without ?,h was measured. Based on viscosity measurements and folding cnain

theory of polyelectrolytes in solution*, the possibility of reactions occuring between macromolecules themselves as well as those with H". have been dieoiieasd. e Wllin •"^

48 III.a.1 ^ •//* GROUND STATE MULTIPLICITY AND ESR PROPERTIES FOR THE d5 CONFIGURATION DOWN TO C CRYSTAL FIELD SYMMETRY APPLICATION TO FERRIHEMOGLOBINS. P. Caro, M. Faucher, H. Pankowska and M. Savy.

Laboratoires de Bellevue du C.N.R.S. 1,Place A.Briand. 92190 Meudon FRANCE

The d configuration involves 252|SLJM. > states in a low symmetry, and without applied magnetic field, each level is doubly degenerate since the scates are coupled as Kramers doublets. We established on the basis of 126 , SLJM > states components of one of the Kramers doublets in a C. symmety, matrix elements for the electrostatic interaction operator with thv tve .'djnstable Slater parameters F and 4 F , the spin orbit interaction operator virn the spin-orbit coupling constant para- meter ^ , a C crystal field interaction, written in Wybourne's tensor operator formalism,involving five crystal field parameters: B" B9, B , B and B.. The technique 5 N applied on d was the i-u^tomarv one useu for f

parame this a; III.a.2 49

EPR STUDIES OF LOW-SPIN CO(II) COMPLEXES D. Attanasio, and M. Gardini Lab. di Teoria e Struttura Elettronica del C.N.R. Via Montorio Romano, j6 ROME (Italy)

The epr spectra of low-spin Co(II) complexes of the type Co(dpe) X , (dpe=l,2-bis(diphenylphosphinc)-ethane; Cio7, NO*, and 2 are being investigated. This note deals with some preliminary results obtained from magnetically diluted powders. No crystallographic in- formation is available on these compounds. However, previous work (W. Levason, and C . A.McAulif f e , Adv . Inorg.Chem. and Radiochem. , _l4_, 173, 1972) showed that square-planar stereochemistry can be assumed with some confidence, at least for the less coordinating counter-ions. Besides g and A principal values (see Table), in all the cases a) TABLE we could measure well resolved hy- CIO, NO. perfine interaction with four, near- 1 2.807 2.760 2.735 2.7*10 ly equivalent 31,P nuclei (when X= -4-1 2 2.475 2.470 2.442 2.455 , A =l8, A =15 xlO cm ). 3 2.001 1.995 1.993 1.998 B

50 III.a.3

ESR INVESTIGATIONS OF THE TRANS INFLUENCE IN TriE NITROSYL ABOUT THE DIRE COMPLEXES WITH LINEAR NITROSYL GROUP TENSORS IN LOV B.Je&owska-Trzebiatowska and A.Jezierski A. Bencini and Institute of Chemistry, University of Wroclaw, 50-383 Wroclaw, Laboratorio CF Florence, Ital Poland In the last symmetry trans The paramagnetic nitrosyl complexes of the formula of the studies [M(dtch) „ (NO) X] (M= Cr, Mn, dtch=dithiochelating agent, as of symmetry cc dithiocarbamate, dithiophosphate, xanthate, X= monodentate priori the pri and magnetic p ligand in trans position to NO coordinating through S, 0 or this is a clea were investigated by ESR method.On the basis of experimental directions of spin Hamiltonian parameters "^Cr, "Mn and N (NO) ' of idealized s chromium complexes) hyperfine tensors were obtained and the Only for spin- chromophores h d electron density on central ion and s and p electron' In order to density or nitrosyl nitrogen were calculated. In virtue of of low symmetr these data it was demonstrated that the trans sulphur ligands single crystal optical and m of the mercaptocompounds type were acting as the % -acceptors betveen the a while trans nitrogen ligands of the amine and azole type symmetries, a were only the donors in relation to the nitrosyl group. assuming the The mutual influence of the dtch ligands and nitrosyl ligand We have no of the directi was also detected and interpreted basing oneself on the midal complex iiSR data. the principal Further they angles, but e the poiarizati Matters ar CoBT3(quinoli that the appa directions ar symmetry. The complexes. Th forced to assi -3/2 •• +3/2 t tely anisotrop to the more fe the g and D te g directions f III.a.4 51

ABOUT THE DIRECTIONS OF THE PRINCIPAL AXES OF OPTICAL AND MAGNETIC TENSORS IN LOW SYMMETRY COMPLEXES. MAGNETIC AND S A. Bencini and D. Gatteschi. V.'illiam E. Hat Laboratorio CNR and Istituto Chimica Generale, Universita di Firenze, Department of Florence, Italy. Venable Hall a In the last years the interest in the spectral properties of low In cotnp symmetry transition metal complexes has largely increased as a consequence expected that of the studies of metallo-enzymes and metallo-proteins. In the absence as the structu of symmetry constraints group theory does not allow to determine a analyses. Thus priori the principal directions of the tensors vhich describe the optical to be dirce ric, and magnetic properties of the complex ( £ , g, A, p, etc). Although interactions w this is a clear cut result it has been customary up to now to assume the Magnetic inte zero mapneti c directions of the principal axes of the different tensors on the basis and sheet poly of idealized symmetry, or, at best, to assume that they should coincide. increases in t Only for spin-hamiltonian tensors the correct formulae POT low symmetry indi cati ons to chromophores have been recently worked out. of their prope In order to provide a tool for the interpretation -f the properties interact!ons w of low symmetry complexes it is required that accurate experiments on single crystals are designed to provide the principal directions of the Recent complexes deri optical and magnetic tensors. Such experiments should show the relations unusual exampl between the actual tensors and those anticipated on the basis of idealized results for >3- symmetries, and allow to appreciate the errors which can be done on a coordination assuming the directions of the axes. the Schiff bas We have now gathered experimental results which allow the determination perpendi cular of the directions of £ , the absorption ellipsoid, in the trigonal bipyra- the four short + Acta Cryst., 2 midal complex Cu(H20)(phen)2 and have found that they are quite close to neighboring m~ the principal directions of g, although they may well be not coincident. _.crv_s_tal h^ axi Further they are rotated from the axes of the idealized symmetry by small behavior in m angles, but even in this case assuming the directions of £ might obscure interaction yi the polarization properties of the complex. state with the magneti zati on Matters are different for the pseudo tetrahedral high spin complex zero-d iinens i on CoBT3(quinoline)*". In this case the esr spectra recorded at 4.2 £ show structure bein that the apparent g values are highly anisotropic and the principal superexchange directions are rotated by large angles from the directions of idealized occurs between symmetry. The values are similar to those observed for similar cobalt(II) the structural complexes. The authors in that case assumed quasi-axial symmetry and were revealed other of these coirpo forced to assign the only observed signal to the highly unprobable -3/2 •"•• +3/2 transition. We have now considered the possibility of comple- tely anisotropic D tensor and have found that the signals can be assigned to the more feasible -1/2 ••* +1/2 transition. Further the non alignment of the g and D tensors can rationalize the large deviation of the apparent g directions from the axes of idealized symmetry.

~i III.a,5

STRUCTURAL AND AND ST^'CTURM. DIMENSIONALITY Derek J. Hodgso William E. Hatfield and William E. Estes Department of C Chapel Hill, Nc Department of Chemistry, University of North Carolina Venable Hall and Kenan Laboratories 045A, Chapel Hill, N.C.27514, U.S.A. The crystal sti chromium(ill) In compounds which exhibit spin-spin interactions, it is usually exchange proper expected that the magnetic interactions will be of the same dimensionality have shown that as the structures which are indicated by crystallographic structural value of the br analyses. Thus, for example, if a complex is known, from x-ray data, we were able to to be diir.eric, then it is certainly expected that the magnetic (D. J. Hodgson, interactions will reflect spin-spin coupling between two magnetic ions. magnetic exchan Magnetic interactions in small clusters of metal ions are said to be of electron at eac zero magnetic dimensionality, with magnetic chains being one-dimensional dimer in additl and sheet polymers being two-dimensional. Thus, systems which show in that the geo: increases in their magnetic dimensionality, despite structural indications to the contrary, are of tremendous interest- since a description (where L is a b of their properties contributes to an understandinp of long-range constant throug] interactions which lead to rragnetic ordering. metal on the ma, and magnetic wo and the structu Recent work in our laboratory on some copper(II) Schiff base complexes derived from salicyaldenyde and n-amino acids has revealed an The data which \ unusual example of dimensionality crossover, The j^ryci-ai ^structure results frr M-sa 1 icy lidene glycinato aquo copper(II) hemihydrate show will be present! ligand L is eth; a coordination plane about copper (TI) of four short bonds, three from derivatives of i the Pchiff base and one from a water molecule, with one longer perpendicular bond from an aminoacid carboxyl oxygen above the plane of crystal X-ray d: an meter. the four short bonds. (T. t'eki, T Ashida, Y. Sasada, and M, Kakudo, /eta Crvst., 22, 870 (1967)),Since the apical bond derives from a neighboring moTecule, a g frn rr,u ra 1 _Ii near chain is formed parallel to the The observed dat b axis^_Fowever, quite surprisingly, the magnetic susceptibility reason for this explained in tei behavior in moderate mapnetic fields are consistent with a dimeric these chromium c interaction yielding a singlet ground state and a low-lying triplet It will be seen, state with the exchange energy, 2J, being -4.3cm . High field dimers of this J magnetization measurements reveal a marked departure from the simple zero-dimensional interaction with a quasi-two dimensional magnetic" structure being formed. The higher dimensionality comes about by superexchange interactions along the chain while the dimeric interaction occurs between pairs of copper ions in adjacent chains. Comparison of the structural and magnetic properties of analogous compounds have revealed other examples of this unusual phenomenon, and the properties of these compounds will be described. ^ III.a. 6 53 *> P j/HAGNETICAI.LY STJ] STRUCTURAL AND MAGNETIC PROPERTIES OF CHROMIUM(III) DIMERS Derek J, Hodgson D.E.Chasan, L.: Department of Chemistry, University of North Carolina a. W.E.Grace Ce Chapel Hill, North Carolina 2751 A, U.S.A. Drexel Oniversi The crystal structures and magnetic properties of a wide variety of di-hydroxo bridged sity,Camden,N.J chromium(III) dimers have been examined in an attempt to correlate their magnetic exchange properties with their structures. For the simpler copper(II) analogs, we have shown that the magnetic exchange parameter, J, is principally determined by the 1,^-Diazine N,N value of the bridging angle, ()>, and that a linear relationship between J and $ exists; through one N-C we were able to explain this on the basis of qualitative molecular orbital theory L.L.Pytlewski,C (D. J. Hodgson, Progr. Inorg. Chem., _19_, 173 (1975)). For the chromium complexes the magnetic exchange is greatly complicated by the presence of more than one unpaired as bidentate br electron at each metal center, which leads to unpaired spin in the ir-system of the metal ions(M—~L dimer in addition to that in the ^-system. There is, however, one simplifying feature^. in that the geometry at chromium in all complexes of the types [CrL2OH]2n+ and [Crl^ORjn oxygen in the I (where L is a bidentate ligand) is pseudo-octahedral and, therefore, approximately cterization stv constant throughout the series. Hence, the influence of changes in the geometry at the metal on the magnetic exchange does not intrude here. On the basis of our structural chlorides and i and magnetic work it has been possible to understand the complex correlation between J type of bridgii and the structural properties, and this will be discussed in detail. ware isolated^ The data which we and others have obtained on di-hydroxo bridged chromium(III) dimers complexes with will be presented. The complexes which we have studied include those in which the ligand L is ethylenediamine, 1,10-phenanthnoline, oxalate, malonate, glycinate, and On the basis JOJ derivatives of dipicolinic acid. In all cases, the structures were solved by single and magnetic B\ crystal X-ray diffraction techniques using data collected on an automatic diffracto- meter. the M-O-M bridj operating via i The observed data show that there is clearly no linear dependence of J on $. The reason for this apparent (but not actual) breakdown for our previous scheme can be racterized by t explained in terms of qualitative molecular orbital theory. Hence, the study of The new metal i these chromium complexes has allowed us to generalize our molecular orbital scheme. It will be seen, however, that the basic hypothesis holds: The magnetic behavior oj- were farmulatei dimers of this general type is determined principally by the M-O-M bridging angle. BM.at 297°K. a type are under! [(OjClOXH^OL.

33

[(O3C1O)(H2O)L

[(O,C1O)(H2O)L and fCC to comprise bo ral features o.

Fe(C10if)2,NiCl. te analogues,a gtwtically non f. 54 III.a.7

'MAGNETICALLY SUBNOEMAL QUINOXALINE 1,4-DIOXIDE TRANSITION METAL COMPLEXES D.E.Chaaan,* L.L.Pytlewski, C.Owens0 and N.tt.Karayannia a. W.R.Grace Ce.,Hatc« Chemical Division,F»rds,N.J. 08863; b. Department of Chemistry, Drexel University,Philadelphia,Pa, 19104; c. Department of Chemistry,Rutgers Univer- sity,Camden,N.J. 08102; d. Amoco Chemicals Corporation,Naperville,111. 60540,U.S.A. 1,4-Diazine N,N-dioxides can reportedly function as terminal ligands,coordinating through one N-0 oxygen or as bridging groups(N.M.Karayannis,A.N.Speca,D.E.Chasan and L.L.Pytlewski,Coord.Chem.Hev.,22i37(1976)). In the latter case,they may act either as bidentate bridging ligands,with each of the two coordinated to different

metal ions(M-oLQ-41) or form M-O-M type of bridges by involvement of a single N-0 oxygen in the bridging of two adjacent metal ions. During recent synthetic and chara-

cterization studies of quinoxaline 1,4-dioxide(qx02 or L) complexes with 3d metal chlorides and perchlorates,several bi- or poly-nuclear compounds,showing the M-O-M type of bridging and characterized by subnormal ambient temperature magnetic moments, were isolated(M=Cr ,Mn ,Co ,Ni ,Cu ). Furthermore,a number of monomeric Fe 2.0 complexes with qxO were also found to be magnetically subnormal for high-spin Fe . 1.5 On the basis of characterization work,by means of infrared and electronic spectra 1.0 and magnetic susceptibility studies in the 80-320°K. region,it was concluded that in 0.5 the M-O-M bridged complexes,^in-spin coupling occurs by a superexchange mechanism, 0.0 operating via the orbitals of the bridging atoms,whereas the Fe complexes are cha- racterized by spin-free(S=5/2)-spin-paired(S=i/2) equilibria( A —TL crossaver). The new metal complexes,which are low-symmetry penta- or hexa-coordinated compounds, were formulated as follows,on the basis of the overall evidence(magnetic moments,in BM,at 297°K. are shown in parentheses; L groups involved in bridging of the M-O-M

type are underlined): [(03C10)2(H20)LCr(L)2CrL(OH2)(OC103)2](ClO^.fii^O (2.54);

[(O3ClO)(H2O)L2Mn(L)2MnL2(OH2)(OClO3)J(ClO,.)^.1OH^O (5.60);[FeCl^(0Ho)J.6H^0 (5.26); 22222 j (4.12); [Fe(OClOJ)L3(OH2)23(ClOit)2.^2O (2.50);

522222;5^22

[(O5ClO)(H2O)L2Ni(L)2Nil2(OH2)(00^)1(010^)2.^0 (2.57); fCtt^Clg^^LgJ.tegO (1.0 and (Ou^OClO^^CR^^L)^(ClO^^-IZHgO (1.5^). The two Cu(II) complexes appear to comprise both types of qxO bridging groups(i.e.,M-O-M and M-QLO-M). The structu-

ral features of a number of magnetically normal qxO2 complexes with CrCl,,MnCl2,

Fe(C10r)2,NiCl2 and Cu(C10^)2,as well as those of the Zn(II) chloride and perchlora- te analogues,are also briefly discussed. It is worth noting that some of these ma- gnetically normal compounds involve M-QLQ-M bridging. III.a.8 55 Y

^ MAGNETIC PROPERTIES OF Co(II) IN Td AND 0, SITES OF SPINEL. EXTENDED CN D.FIORANI, P.PORTA and S.VITICOLI. J-M. Savari LABORATORIO TEORIA E STRUTTURA ELTTRONICA DEL C.N.R. Laboratoi re Via Montorio Romano, 36 ROMA (ITALIA) 3I030-T0UL0 The magnetic properties of Co(II) in the spinel solid solutions An CoRhxGa_ O. have been investigated by magnetic susceptibility measurements in the range (4.2-1000)°K. ' '-M. Savar The Co(II) distribution among the tetrahedral and octahedral si- 1975), 42, tes (available within the spinel lattice) has been found to vary electronics with composition x. This change produces a variation of the ma- transition < gnetic behaviour (see table) Thi: non-emoi ri ci X % Td C TN(°K) 7 T.I.P. vely to the Keff (B.M.) m (e.m.u.) MO Two 2.0 100 2.15 4.15 24 29 582 1.5 72 2.20 4.20 15 31 502 1 - 1.0 56 2.36 4.35 7 54 418 tn smethyl er 0.5 50 2.46 4.44 6 72 94 cenv "Strate< 0.0 29 3.07 4.96 1O 55 18 j£, L 53 (1! with^ that the clc The ^-„ value increasefe/Tncreasing octahedral Co(II) occupation, but occur for (I non-linearity of the variation in C (Curie constant) with compo- fCo.C) bond; sition shows that M- ff(Td) and M' f (Oh) are not constant within (N.J. Fitzp< solid solutions. The TN(Neel temp.) and the negative value of Chem., in pr ©•(Weiss constant) show the existence of ant iferromagnetic inte- ractions. & reaches a maximum value for the composition x=0.5, 2 - suggesting that the strongest magnetic interaction is between SCCC conclus

Co(II)oh and Co(II) ,.TN reaches a minimum value when 0" is highest, J. Organomel

suggesting that the Co(II)o,- Co(II)Td interactions are competiti- of (Mn...CO)

ves with Co (II)TrJ-Co (II) _ - interactions (the latters* produce a tion of the long range antif-erroma^netie ordering) . The temperature indipen- Thu dent paramagnetism (T.I.P.) arises principally from C 4 4 corsuraing s mixing between Ao and T- states and from Rh(IlI) by mixing in the groui between t2 (k1 _.) and t^e ^y^ configurations. instan< to be • system;

I) Y 56 III.a.9 77 .'• EXTENDED CNDO CALCULATIONS ON SOME STANDARD TRANSITION METAL COMPLEXES V ' HIGH-SPIN(5 DEBYE-WALLE J-M. Savariault and J-F. Labarre E. Laboratoire de Chimie de Coordination du CNRS, 205 Route de Narbonne, aInstitut f 31030-TOULOUSE CEDEX (FRANCE) Erlangen-NU Heisse Che An extension of the CNDO formalism was recently proposed The 57Fe Mfi c ; '-M. Savar.ault et ai., Theoret. Chim. Acta, ^6» ^41 (1975), _3Si, 229 high-spin(" i975), 42, 155 (1976), £2, 207 (1976)) allowing the study of the 4.2 and 30C e i ectronic$tructure of mono and polynuclear complexes of first row thickness transition elements. from the mi This method was tested successfully by comparison with previous temperature non-emoirical results on some standard derivatives and applied intensi- "ln fl ' vely to the knowledge of electron distributions in the ground state. Al and A., grc Two significant examples are given here : spin transi The results 1 - the "parachute" (and not "umbrella") structure of the where phen tin smethylenemethane Iron tricarbonyl, (CH2)3CFe(C0), , was clearly cenv rstrated (J-M. Savariault and J-F. Labarre, Irccrg. Chim. Acta, MiJssbauer i 19, L 53 (1976))in agreement with experimental evidences, implying function of that the classical "length versus strength" relationship does not may be well occur for (Fe.C) bonds. The same conclusion was provided about the apply to -1 fCo.C) bonds through a study of the isoelectronic series AM(C0)3 -In f5^2 de (N.J. Fitzpatrick, J-M. Savariault and J-F. Labarre, J, Organometal . -In f value Chem. , i n press). values of t 5 2 - Extended CNDO calculations on Mn2(C0)10 support previous the T2 if SCCC conclusions (O.A. Brown, N.J. Fitzpatrick and A.R. Manning, This is con 5 1 J. Organometal. Chem., 102, C 29 (1975)) about the predominant role T2 and A1 of (Mn...C0) through-space bonding interactions within the descrip- (I), the ch tion of the electronic structure of such a compound. will form a This coupli Thus, Extended CNDO appears to be a time-and-money-non- site to sit corsuming suitable tool for the calculation of electron distributions In compound in the ground state of transition metal complexes. 12 and 3OOK Evidently, , transition i some cases the macrocyclic effect is almost entirely enthalpy driven, in otner instances, however, only entropy or a combination of enthalpy and entropy seem to be important. A comprehensive examination of these various effects for the systems studies will be presented.

-III.a.R.I. 57

V /' HIGH-SPIN( * L0W-SPTN(1A1) TRANSITIONS IN SOLID IRON(II) CHELATES, DEBYE-WALLER FACTORS, AND EVIDENCE FOR DOMAIN FORMATION E. KUnig,a G. Ritter,a W. Irler,a and B. Kanellakopulos aInstitut fur Physikalische Ch'emie and Physikalisches Institut, University of Erlangen-NUrnberg, D-8520 Erlartgen, West Germany Heisse Chemie, Kernforschungszentrum., D-7500 Karlsruhe, West Germany The Fe Mdssbauer effect and magnetism of numerous iron(II) chelates showing high-spin( T-) low-spin( A ) transitions as solids have been measured between 4.2 and 300K. From the suitably corrected areas of the spectra, the effective thickness t$ , e.g., was extracted, whereas the high-spin fraction n5_ obtains

from the magnetic data. Combination of the corresponding results provides the

temperature dependence of the individual Debye-Waller factors -In f5f7 and

-In These quantities are representative for the lattice modes in the T.

and A. ground states and thus afford important information on the mechanism of spin transitions in the solid chelates. The results for two typical iron(II) chelates, viz. [Fe(4-CH3~phen)2(NCS)2] (I) where phen • 1,10-phenanthroline and [Fe(papt)2] (II) where paptH= 2-(2-pyridyl- amino)-4-(2-pyridyl)thiazole are compared. In both (I) and (II), individual

MtJssbauer spectra for ^T2 and ^A^ states are observed, the intensity being a function of temperature. In (I), the values of -In fs_ between 175 and 250K

may be well reproduced bv the Debye model, ^ 5^2 = 126.2K. Similar conclusions apply to -In £i. between 105 and 225K, & 1A-, = 150.2K. However, for T< 175K,

-In f5T2 departs significantly from the Dehye law, the deviation being towards -In f values of the 1A, . Similarly, for T>225K, -In fli-, approaches -In f

values of the ^T2. Normal lattice dynamical behaviour is thus established for the 5T if n5_ > 0.28 (at T >175K) and for the1 A if n . > 0.20 (at T<225K). 2 L • 1 x "1 This is considered as evidence for the formation of individual domains by the T and A molecules at T >175K and T <225K, respectively. If, in compound 5 (I), the change ^-k\ -*• T2 is initiated by thermal excitation, a local distortion will form at one site which is coupled via long wave phonons to other sites. This coupling communicates the distortion and the associated spin change from 5 site to site until distorted arrays, i.e. domains of T2 ground state molecules,obtain.

In compound (II), -In f5-, and -In f iA, have been fitted individually between 12 and 300K, although deviations from the Debye model have not been detected. Evidently, alternate mechanisms for the high-spin(-^2) p: transition have to be discussed in this case. H2EDTA 6.24 0.5 -. 1 13.8 1 . 1xl0"5 methyl este self-consis a 4 NiH_2DGen = 3.5xlO~ M, 25,0 °C, 0,1 M NaC104 and its der

58 Ill.b.l P. MOLYBDENUM COMPLEXES WITH THIOLATO AND DISULFIDO LIGANDS DOUBLETHI 7 ALKALI ME K. Mennemann, D. Altmeppen and R. Mattes Shuvendu Institute of Inorganic Chemistry, University of Miinster Xata Coll Gievenbecker Weg 9, 4400 Miinster, Federal Republic of Germany Bihar, IN 2_ Oxopentachloromolybdate(V), MoOCl. and di-Xt-oxo-bis(oxooxalato- 2- and studi aquo)molybdate(V), Mo 0 (C O ) (H 0) , react with monothiooxalate, 2 4 2 4 2 2 2 Chimica, dithiooxalate-(1,1), dithiooxalate-(1,2), trithiooxalate (W. Stork M and Y.'b and R. Mattes, Angew. Chem. Int. Ed. Engl. _1_4, 436 (1975)), dithio- together squarate-(1,2) and tetrathiosquarate to give a series of mono and dinuclear di-yd-oxo and/or ^-sulfido oxothiooxalato and thiosquarato In

complexes, e.g. Cs2 (Mo202 (jH-S) 2 (COS-COS)2 ) . The structures, spectral MIn(3R)4 and magnetic properties of these new compounds will be discussed. (where M: During the reaction various redox reactions take place, the thio- metals ar oxalate and thiosquarate ligands are partly oxidized. derivati? and Li(Sb( Among the products a sulfur rich compound was isolated, which boiling I was shown to be Cs2(MoO(S2)2(COS-CO2)). Molybdenum is hepta- derivativ coordinate: two disulfide groups (d(SS): 203(2) pm), a bidentate 0,S-ccordinated monothiooxalate and a terminal oxygen atom or K and (d(MoO): 170(2) pm) form a pentagonal bipyramide around the thiols. central atom molybdenum(VI). \O parent it.

\ of NiTRKOH )gT with histidine, 1- and 3-methylhistdine, histamine, histidine

methyl ester, hercynine and imidazole were studied. The results lead to a self-consistent set of reaction paths for the complexation reactions of histidine and its derivatives.

III.b.2 59

DOUBLETHIOL DERIVATIVES Of TRIVALENX AND ANTINOMY WITH /?Jew cationic ALKALI METALS. — — V V Shuvendu Chatterjee. dimethyl fSsf Tata College, CHAIBASA, (Ranchi University),District Singhbhum, S.E.Castillc Bihar, INDIA. D.E.S. FACUI

A good number of double alkoxides MM'(OR) / have been isolated Recencly.it and studied recently (ref. R.C.Mehrotra and A. Mehcotra, Inorg. and several Chimica, Acta.Revs. 5,1^.7,1^71), in wmch two different metals dimethyl 1,] M and M*having valencies, n and n'respectively, have been linked different pc together with the aid of alkoxy bridges. of the unusi of interest In view of the above, two series 0/ doublethiol derivatives behavior. Fc Mln(SR),, (where M— Li, Na or K and R= Pr or Bu) and MSb(SBu ), * 4 the type pyi (where M= Li, Na or K) containing two diii'erent petals (alkali dimethvLsulp aietals and trivalent indium or ) have been isolated. The acetonitrile derivatives containing lithium Li(Jn(SR), (where R= Pr or Bu) nature. In t

and LiSb(SBu ). were found to be monomeric ebullioscopically in "bus > for Ii? boiling parent thiols and chloroform respectively, whereas the compounds oi

derivatives containing sodium and potassium Mln(SR), (wnere K-s Na in CH2C12 g: or K and Rss Pr or Bu) appear to dissociate in boiling parent not enter as thiols. In the case of trivalent antimony, these derivatives tne species MSb(SBu ). (where M = Na or K) were found to be insoluble in occur in noi parent thiols and in all other common organic solvents. atom. Another insi is reacted ^ in the same

*CH-C1 com 60 III.b.3 v

catianic,anionic and neutral Ruthenium(LII) and (II) compounds containig METAL CHE] / dimethyl Pienyl1- phosphine and N,O,S ligands. Stanley E, S.E.Castillo Blum and L.Ruiz-Ramirez School of D.E.S. FACULTY OF CHEMISTRY U.N.A.M. Mexico 23 d.F. The S< and Pr1) 1

Recently,iC has been reported the reactions between raer-RuCl (PM?0) (A) semicarba: and several ligands of the type 2,2' bipyridyl; 1,10 phenantliroline,2 ,9 thiol fon dimethyl 1,10 phenanthroline^j^i7,8 tetramethyl phenantroline.in solvents of similarly different polarity. (L.Ruis-R.J.Chem.S.(Dalton),2244 1975). In view carbazate. of the unusual behavior of this compound(A) against those ligands,we considered bases cant of interest to extend the range of ligands in order to observe its pattern of R-C= behavior. For this purpose we reacted (A) with some other N,O,S ligands of I 0B the type pyridine;2,6 lutidine>2,4,6 collidine;4,7 diphenyl 1,10 nhenatroline, dime thyLsulphide,etilendamiadine,oxalate ion,acetilacetonate ion,aerylonitrile, acetonitrile.obtainig different products defending, on the lii^and and solvent MLure. In the present work are discussed the dtaeAls of each one the products. The tb "hus>;"or lie;ands such as pyridine,lutidine and collidine ( L ) in methanol, to metal i R compounds of the type Ul C uCl 01Ie(PMe 0)^^ OJ are obtanied,while the reaction doubly neg ?Y in CH Cll gives [RuCl (PMeo0 )o 7J (i.e.L=py). The reason for which L does only they not enter as a ligand is due to its previous reaction with the solvent giving of bo-ch ty tne species LH OMe,avoiding L to coordinate to the Ru atom; this does not compounds

occur in non polar solvents as CHOC1? and ligand L coordinates to ruthenium nickel com atom. [Ni(0NS)py Another instance is when bidentateligands such as 4,7 diphenyl phenatroline (M = Pd, F

is reacted with A in MeOHthe compound[RuCl(PMe 0 ), 4,7 di 0 nhen CH.ClJ Cl The su in the same way that occurs with 1.10 phenathroline. behave as and platin *CH_C1. comes from recrystallization. which are nigh-spin with a pse

octahedral diamagneti about a chi with ferrii of solts decreases in the following succession: results ui V(CN), VOCCN). between mi

/ -V III.b.4 61 /

METAL CHBLATBS OF LIGANDS CONTAINING THE ONS DONOR GROUPING :•/ Stanley E. Livingstone and Justin E. Oluka CHEMICAL ANI

School of Chemistry, University of New South Wales, Kensington, N.S.W. 2033, Australia P. Gouzerh, The Schiff bases (I; R = 2-thienyl, Ph, p-BrCgH., p-MeCgH., p-MeOCgH,, 3-naphthyl, Laboratoire and Pr1) have been prepared by condensation of fliurinated p-diketones with thio- Marie semicarbazide. In solution these compounds are in equilibrium with the tautomeric ene- Althc thiol form (II). The Schiff bases (III; R = Ph, p-MeCgH R' = Me; R = R' = Ph) have H. Bauer, Be similarly been obtained by condensation of 3-diketones with N-methyl-S-methyldithio- used as ligi carbazate. Since in these compounds the nitrogen atom is methylated, these Schiff 68, 601 (19'i bases cannot form an ene-thiol tautomer analogous to (II). 409, 285 (1< R-OCH-C-CF R-OCH-C-CF R-C=CH-C-R' ions in sevc 3 I 3 OH N OH N OH N assumed conf I m (i) N (ID N-CH (Ill) hydroxyamide H c C C to the amide t/\ // \ HS S SCH. activity. Th S NH 3 chemistry of The thiosemicarbazide Schiff bases in their tautomeric form (II) can coordinate solution che to metal ions in two ways: (a) by the loss of the OH and SH protons they can act as infrared anc doubly negatively charged ONS tridentate ligands or (b) by the loss of the SH proton only they can behave as singly negatively charged NS bidentate ligands. Complexes With of boxh types were isolated. All the Schiff bases give dimeric i.-dithiolo-bridged which was pi late and hyc compounds of the type ^M(ONS)j? (M = Ni, Pd, and Pt). The thiolo-bridges in the nickel complexes can be split by reaction with pyridine to give the monomeric compounds both clearly [M(0NS)py], When R = 2-thienyl or p-BrCgH., 1:2 complexes of the type ~M(H0NS)_] bis-complexe (M = Pd, Pt) were also isolated. complexes we was carried The substituted dithiocarbazate Schiff bases (ill) by the loss of the OH proton Mn , behave as singly negatively charged ONS tridentates. Copper(ll), (ll), which were i and platinum(ll) form the four-coordinate complexes [M(0NS)Cl] (M = Cu, Pd, Pt), or electroch which are non-electrolytes in dimethylformamide. On the other hand, cobalt(ll) forms On the other high-spin complexes of the type [Co(0NS)2J; their electronic spectra are consistent with a pseudo-octahedral configuration. Nickel(ll) also forms 1:2 complexes, viz. Preli 1 low-spin con ;~Ni(0NS)2j. When R = K = Ph, the complex is high-spin (JJ., 3.2 BH) and pseudo- octahedral. However, when R - Ph, or p-MeCgH. and R = CH_, the complexes are Infra diamagnetic and square-planar, indicating that a change in the R1 group can bring the same coo about a change in spin-type and stereochemistry. Reaction of the Schiff bases (ill) ferrate(II) and one nitr with ferric chloride yields the high-spin complexes (Fe (ONS)9J[Fe Cl.]. results Che ferrihemoglobins can De round on ei.LLiCl = ^ ~ - d 2 grc between multiplicity 2 and 6 in between the two triple points. z par etmei this ai

62 III.b.5 Y L ^ / THE SY • V/ WITH S CHEMICAL AND STRUCTURAL STUDIES OF SOME COMPLEXES INVOLVING ETHYLNITROSOLATE AS A LIGAND S. 0. P. Gouzerh, Y. Jeannin, C. Rocchiccioli-Deltcheff and F. Valentin! Laboratoire de Chimie des metaux de transition (ERA CNRS n° 608), Universite Pierre et Marie Curie, 4 place Jussieu, 75230 Paris Cedex 05, France. Although the nitrosolate ions have been known for a long time (H.1 Wieland and H. Bauer, Ber, dtsch. chem, Ges., 39, 1480 (1906)), they do not appear to have been used as ligands until recently (F. Valentin!, P. Gouzerh and P.' Souchay, J. Chim.' Phys., 68, 601 (1971); 69, 689 (1972); J. Kopf, G. Vetter and G. Klar, Z, anorg. allg. Chem., 409, 285 (1974)). However they have several interesting features: they can bind metal ions in several ways, as monodentate or bidentate ligands, depending on the ligand assumed configuration (syn-anti, anti-anti or syn-syn); they can be easily reduced to hydroxyamidoximes which also are effective ligandsj the nitrosolic acids are related to the amidoximes and the hydroxamic acids which are known to have some biological activity. These reasons led us to undertake a systematic study of the coordination chemistry of the ethylnitrosolate/hydroxyacetamidoxlme redox pair,' Some aspects of the solution chemistry, mainly redox reactions, and of the crystal chemistry, i.'e. X-ray, infrared and magnetic data, of the Mn, Fe, Co and Ni complexes will be discussed. With nickel the most important result is the exceptional stability of a compound which was proved by X-ray analysis to be a mixed complex of Ni(II) with ethylnitroso- late and hydroxyacetamidoximate anions. It is the first example of a complex containing both clearly individualized forms of a quasi-reversible pair of ligands. The parent bis-cotnplexes were also prepared and the redox reactions between the mixed and bis- complexes were studied by electrochemistry.'A detailed IR study of these complexes was carried out. Mn , Fe and Co react with ethylnitrosolate anion (L~) to give ML_~ complexes which were isolated as tetrabutylammoniuro salts.' The three compounds can be chemically or electrochemically oxidized to neutral ML- complexes isolated only for Fe and Co. 2- On the other hand, they can be reduced to ML, " species,* Preliminary magnetic results show that all solids of the ML," and ML, types are low-spin compounds, indicating that ethylnitrosolate is a strong-field ligand.' Infrared spectra are consistent with the fact that all the ML_n" complexes have the same coordination structure.' The of cesium tris(ethylnitrosolato) ferrate(II) monohydrate shows that each ligand is bidentate through one oxygen atom and one nitrogen atom with the three nitrogen atoms lying on an octahedron face. d 2 z ground-state. Fair agreement between experimental and calculated parameters could also be obtained with a fitting calculation based on this assignment.

V % III.b.6 63 J.' THE SYNTHESIS &ND .CHARACTERIZATION OF ANTIMONY (III) COMPOUNDS V- WITH SEVERAL TJIIOLIGANDS S. 0. Wandiga Department of Chemistry, University of Nairobi, Nairobi, Kenya.

i The preparation, H nmr and ir spectra of antimony(III) compounds with 3,3-dimethyl-cysteine, N,N-disubstituted-dithioxamides and N,N-disubstituted-dithiomalonamides will be reported. The synthesis of the N,N~disubstituted-dithiomalonamide chelates are new and will be reported for the first time. The ligands show extensive hydrogen bonding both in the solid and liquid states. The antimony(III) compounds constitute a series of several compounds that have been studied for possible use in schistosomiasis treatment. 64 III.b.7 Tuesday, HETEROCYCLIC PENTATOMIC LIGANDS CONTAINING THE THIO- OR SELENO-AMIDIC GROUPS. F. Cristiani, F.A. Devillanova and G. Verani Istituto Chimico Policattedra dell'Università di Cagliari, 9.00 h Via Ospedale, 72 - O91OO Cagliari, Italy. 9.20 Heterocycl.f c pentatomic rings, such as X- CH2 • CH2 ' CY>NH, where X = CH2, 0, 9.40 S, NH, NCH3 or NC2H5 and Y = S or Se, show some industrial and biological 10.00 importance and they seem to he interesting ligands in the coordination 10.20 chemistry, because they have two or three different atoms able to coordi- 10.40 nate in competition. The stability of the above rings mostly depends on the X substituent, and only for 1,3-oxazolidine-2-thione (X = O) a ring opening was sometimes verified. Many complexes with these ligands were recently obtained (F. Cristiani, F.A. Devillanova and G. Verani, unpublished data)," we want here to report the results obtained by reaction among the IIB group halides and 1,3-oxa- 11.15 zolidine-2-thione (F.A, Devillanova and G. Verani, J. Coord. Chem., sub- mitted), l,3-imidazolidine-2-thione (X = NH and Y = S) and -2-selone (X = *= NH and Y = S) (F.A. Devillanova and G. Verani, Transition Met. Chem., in the press) and pyrrolidine-2-thione (X = CH2 and Y = S) (F. Cristiani, F.A. Devillanova and G. Verani, Transition Met. Chem., in the press). All the complexes have general formula ML2X2J where M = Zn, Cd and Hg, L = one 9.00 of the ligands and X = Cl, Br, I. The reactions between Zn(ll) halides and 9.20 Hg(ll) iodide and 1,3-oxazolidine-2-thione did not produce well defined complexes in consequence of the ring opening. This breaking has been in- S. 40 terpreted as an acid catalysis of Zn ion and a nucleophylic attack of 10.00 the iodide ion on the carbon near the oxygen atom in the ring. All the 10.20 complexes are S- or Se-bonded to the metals; the coordinating atom was identified by comparing the i.r. spectra of the complexes with those of 10.40 the free ligands and considering the shifts of the bands previously as- signed (F. Cristiani, F.A. Devillanova and G. Verani, J.C.S. Perkin II, in the press; F.A. Devillanova and G. Verani, J.C.S. Perkin II, submitted) to the -X-CY-NH- groups. Tuesday, July 19, 19 77

Room A Room B

9.00 h E.R. Dockal M.S. Masoud 9.20 P.. van Eldik C. Floriani 9.40 T.J. Meyer J. Gazo 10.00 A. Ha im I.A. Zakharova 10.20 F. Garnier L. Malatesta 10.40 W. Strohmeier Y. Dartiguenave R. van Eldik I 0)

11.15 K. Taube CO •o CO

Room C Room D

9.00 Y. Gushikem M. Costas 9.20 S.C. Grim J.M. Riveros c .40 M. Trabelsi E. König 10.00 J.R. Anacona D. De Filippo 10.20 G. Mitra 'j.A. Konigstein 10.40 D.S. Payne D. Craciunescu J.R. Anacona

1 Tuesday, July 19, 1977 I TWO OUTSTANDIN Room A Room B G.H.M.Dias, £. 13.45 h S. Kirschner University of 14.20 F. Galembeck M.R. Udupa Caixa Pestai 2 14.40 E.J.S. Vichi M. Massacesi 15.00 Y. Hase I.B. Bersuker L) The value 15.20 M.A. De Paoli S.K. Sahni R. Mattes compared to m<

it should be r 16.00 K. Sone 0. Piovesana been verified 16.20 H.L. Chum V.l. Spitsyn 16.40 M.I.D. Holanda Y. Yamamoto in considerab:

17.00 A.M. da C. Ferreira V.L. Goedken some of their 17.20 O.A. Serra L. Fabrizzi decomposition 17.40 J. Costamagna N.Y. Murakami L.N. Pankratova formation of :

adherent to t)

the surface o Room C Room D drastic modif

14.20 G. Tosi D. Sutton which is very 14.40 S. Asperger M.Y. Darensbourg means (F.Gale 15.00 D.W. Franco M.W. Lister 15.20 F.J. Aymonino H. Barros 2. A dérivât

C. Battistoni Its coordinat

ability to co 16.00 L.A.A. de Oliveira J. Miller 16.20 W.J. Louw M.M. Singh thermodynamic J.C. Bhatia 16.40 A.L. Rheingold the complex f 17.00 B. Chakravarty G. Schmid enthalpic con 17.20 V.N. Pandey 17.4C JK.L. Tobe E. Mendelcvici D. Soria L. do Amaral C. Floriani te aiialoguea,i gn«tically noj

!- , •U' i KMS.l 65

TWO OUTSTANDING PROPERTIES OF IRON CARBONYLS [IRON CARBONYLS G.H.M.Dias, F.Galembeck, J.F.Rodrigues and V.Araujo F9 Eduardo J.S^ Vi

University of Sao Paulo, Institute of Chemistry * Instituto de Qu t University Cheir Caixa Postal 20.780, Sao Paulo, Brazil In recent years synthetic organ 1) The value of Hildebrand's solubility parameter (6) for Fe(CO)5 is very low, as in Organic Synt types of rearti compared to most organic or inorganic liquids. It is thus possible to predict that an 'activating' chemistry of me it should be miscible with many low-6 liquids, including fluorocarbons. This has alternatives, a the second. been verified experimentally: Fe(CO) is sorbed in amorphous polytetrafluoroethylene, One of the tnajo in considerable amounts. It is then possible to have the iron carbonyl displaying has been to fin* molecules under some of their well-known chemical properties in the plastic matrix: oxidation, photo- covery that (bei readily undergoi decomposition to Fe2(C0)g have been found to occur with the sorbed FeCCOK. The B.F.G. Johnson, Since then many- formation of iron (III) oxide is particularly important: the oxide formed is strongly prepared. The | and its utility adherent to the polymer and it can be prepared both inside the plastic pieces or at The reactivity < the surface of the polymer. The result of surface impregnation of the polymer is a be substantiall; Soc. Dalton Trai drastic modification of the superficial properties of the low surface energy plastic, are involved de] as a directing ; which is very difficult to accomplish by any (chemical, photochemical, radiolytical) will be discuss* at the 'outer' i means (F.Galembeck, J.Pol.Sci.Pol.Let.Ed., in press). diene fin) or as well as the 2. A derivative of Fe(CO) , the anion Fe(CO), is a very strong, b-type ligand. Finally, the us< Its coordinating ability has been studied and it is found to have an outstanding coordinated org, ability to coordinate and in aqueous solution. The evaluation of the

thermodynantic parameters for the cadmium complexes and HFe(CO), formation shows that

the complex formation and the protonation reactions both depend largely on the Pe (co

enthalpic contribution. l

E.J.S.V. thanks financial suppoi a Scholarship. te analogues,are also briefly discussed. It is worth noting that some of these ma- gnetically normal compounds involve M-QLQ-M bridging.

f 06 KMS.2 0

\ )/ 0 'IRON CARBONYLS AS ACTIVATING AND PROTECTING GROUP IN ORGANOMETALLIC CHEMISTRY. / VIBRATIONAL * + I" c yS-. yj- .hii Aubrey L. Burrows, G. Richard Stephenson. A. E. Mauro1 # Instituto de Quimica, Universidade Estadual de Campinas, Campinas, Brazil. 'Departamento t University Chemical Laboratory, Lensfield Road, Cambridge, England. C.P. 14800, A Campinas, C.P In recent years it has been established that the group Fe(CO)3 has utility in synthetic organic chemistry (Birch and Jenkins, 'Transition Metal Organometallics in Organic Synthesis', Academic Press, London, 1976, Vol 1). Two different Vibrational R types of reaction have been investigated: (i) The use of the Fe(COs group as 3 been reported an 'activating,' moiety, (,ii) the Fe(CO)3 group as a 'protecting* group. Tne chemistry of metal dienyl complexes will be used to illustrate the first of the some interest alternatives, and the use of the Fe(CO) group to give natural product derivatives^ 3 out. In this the second. dien, trien, One of the major problems encountered with the chemistry of Fe(CO) derivatives 3 sidering the has been to find a suitable mild method of combining the Fe(C0)3 group with the molecules under study. To a large extent this problem was overcome by the dis- groups as sho' covery that (benzilidenacetone)Fe(C0) , an easily prepared heterodiene derivative, 3 trien, and gr< readily undergoes dissociation to produce the active Fe(CO)3 unity, (j.A.S.Howell, B.F.G. Johnson, P.L.Josty, J. Lewis, J. Organometallic Chem., 3°., 329 (1972). possible stru Since then many previously inaccessible (diene) Fe(C0) derivatives have been 3 and C. . The prepared. The preparation of (benzilideneacetone)Fe(CO)2L (i) (L = CO, R3P, (R03P) and its utility as Fe(CO)aL precursors will be discussed. follows: r(C3. and T(C. -pol The reactivity of an organic molecule coordinated to a Fe(C0)2L grouping can be substantially modified by changing the ligands (J. Lewis, et. al. J. Chem. analysis was Soc. Dalton Trans. Ifffct, 2093 and 2105). Electronic, steric and kinetic factors results of vi are involved depending on L, diene and reactant species. Utilisation of Fe(C0)2L as a directing group in nucleophilic reactions of dienyl carbonium ions (il) that the skel will be discussed. Depending on L, diene and nucleophlle the attack can occur polymer. To c at the 'outer' or 'inner' carbon atom in the dianyl function leading to •',"'»- diene fin) or (f Tf-allyl (IV) products. Some examples will be discussed least squares as well as the stereochemistry of the nucleophilic attack. tive assignme distributions Finally, the use of Fe(C0)2£ as a protecting group for the diene function in coordinated organic molecules will be discussed, for these com + »

Table 1. VCO

R 3 3 I

R dien I

R E.J.S.V. thanks the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo for trien I financial support. A.L.B. and G.R.S. thank the Science Research Council for a Scholarship. Dezween x... -) and t^e configurations.

KMS.3 67

/ VIBRATIONAL SPECTRA AND STRUCTURES OF SOME L ZnFe(CO), COMPOUNDS (1,3 -Diene) / n 4 1 2 Spectra and Ï A. E. Mauro and Y. Hase M.A. De Paoli

'Departamento de Quïmica, Faculdade de Filosofia, Ciências e Letras de Araraquara, Max-Planck Ir C.P. 14800, Araraquara, Brazil. zInstituto de Quïmica, üniversidade Estadual de a.d, Ruhr, W. Campinas, C.P. 1170, Campinas, Brazil. *Max-Planck 1

Vibrational Raman and infrared spectra of some Fe(CO),. derivatives with ZnL have Three e» been reported (A. E. Mauro, Thesis of D.Sc, Üniversidade de Sao Paulo ( 1976)) and the title con some interesting aspects of the bonding and molecular structures have been pointed and the 1,4-d out. In this study, the vibrational spectra of L ZnFe(CO),, where L is (NH-)_, pyridine-ani1 dien, trien, tn, s-diMeen and Meen, are analyzed on the basis of group theory. Con- compounds wer sidering the CO stretching frequencies, the compounds can be classified into two titution of o groups as shown in Tables 1 and 2; group A includes compounds with (NH,),,, dien and gands and pho trien, and group B those with tn, s-diMeen and Meen. For a monomer, there are two ce of excess possible structures, C, and C„ ; two structures are possible for a polymer, D,, by X-ray ana and C. . The representations for fundamental CO stretching modes are given as be described

follows: F(C, -monomer)«2a+e, T(C„ -monomer)=2a.+b1+b_, T(D, - polymer)=a.. +b. +e , atoms of BIPY

and F(C„ -polymer)=2a.+b..+b?. For these four skeletal structures, normal coordinate BPpMA are mix analysis was carried out with the assumption of a general valence force field. The cture of the 1 results of vibrational selection rules and normal coordinate calculations indicate fi st rikii that the skeletal symmetry of group A is C2 -monomer and that of group B is C. - the apparent . polymer. To clarify the nature of the bonding, force constants were adjusted by the By analogy thi least squares method to reproduce the observed skeletal frequencies, and the tenta- system. They tive assignments of Raman and infrared spectra confirmed using the potential energy difference in distributions. These results are compared with those of extended Hückel calculation NMR spectra i for these compounds. ne groups, pri the two nitroj Table 1. vCO region of group A Table 2. vCO region of group B posi ti ons. Ii band positions , . R 1945,1855,1818,1797 R 1985,1899,1853,1819 imposed bands ^ 3;3 I 1945,1855,1821,1801 tn I 1967,1946,1890,1856 between 17 an< R 1941,1835,1825,1784 R 1989,1902,1874,1828 dien s-diMeen lkK going fror I 1941,1840,1825,1789 I 1974,1959,1901,1851 UV-visible anc R 1923,1842,1809,1789 R 1988,1900,1880,1849 Meen and discussed. trien I 1925,1834,1803,1787 I 1993,1964,1880,1845

M.A. De Paoli

• li-Mii^* ' n^Mja^àk 12 and 30UK, Evidently, &'. transition hi

68 KMS.A

(1,3 -Diene) ( 1 , 4-Diaza-1 , 3-Diene)Monocarbony1iron Complexes: Syntheses, THERMOCHRC Spectra and Structure, K. Sone M.A. De Paoli, F.W.Grevels, H.W. Fruehauf and C. Krüger*. Department Max-Planck Institut fur S t rah 1 enchéri : e , Stiftstrasse 36, D-4330 Mülheim Otsuka,Bur a.d, Ruhr, V. Germany. Metallic c *Max-Planck Institut fUr Koh1enforschung. slight hes Three examples of a new type of mixed complexes have been prepared, photometr: the title complexes, where the diene ligand is diet hy lmucon ate (fU[CO) have led 1 and the 1,A-diaza-1,3-diene ligands are 2 , 2'-dipyridi1 (BIPY), 2-benzoyl 1) The bli pyridine-ani 1 (BPA) and 2-benzoylpyridine-p-methoxyani 1 (BPpMA), The and then : compounds were obtained as brownish-red crystals from the thermal subs- methanol, \ titution of one diene ligand of (MUCO)2Fe(CO) by the respective DAD li- quite eas: gands and photocheiri cal ly by irradiation of (MUCO) F e (CO) 3 in the presen pink take: ce of excess DAD ligand. The structure of the BIPY complex was determined hand,the < by X-ray analysis. The coordination around the central Fe atom can nounced. ' be described as a distorted square pyramid with one of the nitrogen alkyl groi atoms of BIPY occupying the apical position. The complexes with BPA and 6-coordini BPpMA are mixture of isomers. The spectral data indicate that the stru- 2) Hexanie- cture of the main isomers is analogous to (BIPY)(MUCO)Fe(CO). mostly pi] 1 Z striking feature on the MUCO ligand part of the *H-NMR spectra are up to ca.. the apparent doublets at 8.14 and 10.00 d" (for (BIPY)(MDCO)Fe(CO) ). Ni (II) coi By analogy they are assigned to the two central protons of the diene NiCl2.. system. They are remarcahle by their large downfield shift and their difference in chemical shifts. Another interesting feature on the ^H- All these NMR spectra is the diastereotopic splitting in one of the two methyle- hmta in p ne groups, precluding molecular symmetry and demanding a structure with ordinatio: the two of BIPY occupying nonequivalent e.g. basal and apical the coord, positions. In the IR spectra of the compounds the intense CO-stretching anions» 1 band positions are between 1900 and 1930 cm" . A great number of super- 3) Spectn imposed bands are observed in the UV-visible spectra in the region from Hue between 17 and U0 kK, These show a solvent dependence of the order of in the re< 13 lkK going from benzene to diroethy1 su 1 foxide, The lH- and C-NMR, IR, a very st: UV-visible and MS spectra results, and the structure, will be presented the total and discussed. creases r<

M.A. De Paoli thanks a research fellow from the Humboldt Stiftung. 12 and 300K, although deviations from the Debye model have not been detected. 5 Evidently, alternate mechanisms for the high-spin( T2) F^ transition have to be discussed in this case.

KMS.5 69 f THERMOCEROMISM OP METALLIC COMPLEXES IN SOLUTIONS AND CRYSTALS ELECT K. Sone Department of Chemistry Ochanomizu University Otsuka,Eunkyo-ku,Tokyo 112,Japan Helena Li d Metallic complexes sometimes change their colors quite drastically,by (1) Institut slight heating or cooling,either in solutions or in crystals. Spectro- (2) Departs Coloradc photometric studies on a few examples of such thermochromic phenomena have led to a number of interesting findings such as the following: The ct 1) The blue color of the alcoholic solutions of CoCl, becomes violet, iron(II) dii and then finally pink,upon cooling. This change occurs most easily in R,R'=H,H; H, methanol,vhere the solution is already violet at room temperature,and where R, ,R2 = quite easily in various primary alcohols,where the change from blue to or 1,10-pher pink takes place between room temperature and ca.-50°C. On the other sthylpyridir hand,the color change observed in secondary alcohols is far less pro- acidity medi observed in nounced. This can be ascribed to the steric effect of the branched * alkyl groups in secondary alcohols,which hinders the formation of pink t, —* TT . Th 6-coordinated complex species at low temperature. correspondin 2) Kexamethylenetetramine (hinta) complexes of Co (II) and Ni(II) are are one-elec mostly pink and groen,respectively,but when their crystals are heated on the iron up to ca.l50°C,the Co(II) complexes becomes blue or violet,while the compared to Ni(II) complexes change sometimes in more complicated ways,e.g.: intensity vi

NiCl2.2hmta.l0l!2O NiCl2.2hmta.2K2O in the corre Oreen Yellow Violet indicate tha All these color changes are caused by the coordination of anions and the acceptor hmta in place of the water molecules driven off by heat from the co- the medium, ordination sphere,and careful studies on them clearly indicate that of luminesce the coordination tendencies of these ligands are in the order H_0^> Additi anions» hmta. salt/benzene

3) Spectrophotometric data on the familiar color change of CuSO,.5H2O vhereas the from blue to white accompanying its dehydration shows that the d-d band constant wit in the red is shifted slightly to the infrared,but,at the same time, the decrease a very strong charge-transfer band appears in the ultraviolet,so that that Lewis a the total light absorption in the near uv-visible-near IR region in- due to the f creases remarkably in spite of the disappearance of color.

Acknowledgme Fundacao de Army Resear 70 KMS.6

* '<• ELECTROCHEMISTRY AND PHOTOCHEMISTRY OF IRON DIIMINE COMPLEXES iPECTRAL AND s' \° IN A ROOM TEMPERATURE MOLTEN SALT IN AQUEOUS A 12 2 P. Krumholz Helena Li Chum ' and R.A. Osteryoung (1) Instituto de Quimica, Universidade de Sao Paulo, Sao Paulo, Brasil an Instituto de (2) Department of Chemistry, Colorado State University, Fort Collins, 1) Deceased Colorado 80523, USA. 2) Permanent The chemical, electrochemical, and photochemical behavior of eleven Fortaleaa 2+ Iron(II) diimine complexes (FeL3 , L = CH3N=C(R)-C(R')=NCH3 where The syste

R,R'=H,H; H,CH3; CH3,CH3; CgH^H; -CH2CH2CH2CH2-; L = C^N-C (R^ =NR2 in acetonit

where R][,R2=H,CH3; CH3,CH3; C6H5,CH3? CgH5CH3; CgH^CgHg,- 2,2'-dipyridine Prepared. Tti or 1,10-phenanthroline) was studied in the 2:1 aluminum chloride: by molecular sthylpyridinium bromide room temperature molten salt. In this high Lewis 100(acetonit acidity medium all the complexes exhibit strong color, similar to that and magnetic observed in high proton acidity media, due to the inverse charge transfer The absoi t~ —> IT . The iron (II) complexes can be electrochemically oxidized to the or acetoniti corresponding stable iron(III) complexes. All electrochemical oxidations pendence. Fc are one-electron reversible processes. The influence of the substituents band centers on the iron diimine chromophore in this medium will be discussed and temperature compared to 10 M H-SO. and acetonitrile. Upon irradiation with low the shouldei intensity visible light, all iron(II) diimine complexes are transformed temperature in the corresponding iron(III) complexes in high yield. Preliminary dat*i and the shot indicate that the complexes in the excited state transfer electrons to reproducible the acceptor ethylpyridinium present invery high concentration (3.3 M) in re for a pel the medium. The kinetics follow that for the electron transfer quenching acetonitrilf of luminescent excited states. absorptivit: Addition of benzene to the molten salt e.g., to 50% v/v molten brium shoulc salt/benzene, causes a ca. 100 mV increase in half-wave potentials, viously ass« whereas the potential for under the same conditions is tris(2-amin<

constant within 10 mV. This increase of E./2 is also observed with Soc, 89,63: the decrease of proton acidity. These reasults and nmr studies indicate In order that Lewis acidity is decreasing not only by a dilution effect but also susceptibil: due to the formation of new species CgHgAlX,. rements cle£ the ratio oi presence of Acknowledgment: The authors acknowledge financial support from the ty of the s Fundacao de Amparo a Pesquisa do Estado de Sao Paulo and the U.S. Army Research Office (Durham) . KMS.7 71

AND MAGNETIC PROPERTIES OF TRIS(2-AMINOMETHYLPYRIDINEURON(II) KINETIC AQUEOUS AND NON-AQUEOUS SOLVENTS METHYLIKINi 1 2 A.K.G. and Helena Li Chum P. Krumholz , M.I.D. Holanda , J.A. Vanin, Departs Instituto de Quimica, Universidade de Sao Paulo, Sao Paulo, Brasil Caixa F 1) Deceased August, 1973 2) Permanent address: Centro de Ciencias, Universidade Federal do Ceara, Trie- Fortalesa, (Brasil) in acidic a The system tris(2-aminomethylpyridine)iron(II) was studied in aqueous solutions and A.M.G. da C in acetonitrile. The perchlorate and hexafluorphosphate salts of the complex ion were Spect. Prepared. The complexes are labile in water or acetonitrile, and very easily oxidized molecular o: by molecular oxygen. If an excess of ligand (ratio [ligandj: (j:omplexji 200 (water); bond rupturi lOO(acetonitrile) ) is added to the complex solution at controlled pH, the spectral to oxidatio: and magnetic properties of the compounds can be studied under an inert atmosphere. experiments The absorption spectra of the perchlorate or hexafluorphosphate solutions in water out of the t or acetonitrile, in the presence of excess ligand, show a remarkable temperature de- that the re* pendence. For the perchlorate complex in acetonitrile at 30 C, the spectrum shows a order with ] band centered at 435 nm with a shoulder towards longer frequencies. By increasing the in a pre-eqi temperature to 60°C the absorption maximum at 435 nm decreases by a factor of 3, and while iron ( the shoulder becomes a pronounced maximum at 375 nm. Conversely, by decreasing the Compaj temperature from 30 to 10 C, the absorbance at 435 nm increases by a factor of 1.5, takes place and the shoulder becomes less pronounced. By varying the temperature from 5 to 65°C, carbon. It j reproducible spectra within the experimental error can be obtained at each temperatu complexes tc re for a period of 3 hrs.. The temperature dependence exhibited both in water and in A mecl acetonitrile cannot be explained solely on the basis of temperature-dependent molar bi sine thy lino absorptivities. These data indicate that a high-spin ( T») - low-spin (A.) equili- followed by brium should be operative in solution. Temperature dependent magnetism had been pre- viously assessed in the solid state for the Cl and Br but not for the I~ salts of tris(2-aminomethylpyridine)iron(II) (G.A. Renovitch and W.A. Baker Jr., J. Am. Chem. This v Soc, 89,6377(1967) ). Estado de Si In order to confirm the existence of the magnetic isomers in solution, magnetic susceptibility measurements were performed by using the method of Evans. These measu- rements clearly indicate the high-spin^=t low-spin equilibrium in solution. At 30°C, the ratio of concentrations of the low to high-spin forms is of the order of 6. The presence of labile high-spin form was also confirmed by EPR measurements. The intens_i ty of the signal with a g*1.950 was shown to be temperature-dependent. Dece

—| &DOUU et UX1C& with ferric

72 KMS.8 KINETICS AND MECHANISM OF THE AUTOXIDATION OF T>,IS-(BIACETYLBIS - METH7LIKINE) IRON (II) LANTHAHII A.K.G. da Costa Fen-eira, P. Krumholz and J.M. Riveros Q.A. Sen Departamento de Quimica Fundamental Universidade Sao Paulo Caixa Postal 20 780 Sao Paulo, Brasil 1) Instr 2) Insti

TriB-(biacetylbismethylimine) iron (TT) undergoes autoxidation in acidic aqueous media through a free-radical process ( H.L.Chum , Perchior A.M.G. da Costa and P. Krumholz, J.C.S., Chem. Comm., 1972, 772). lanthanii Spectrophotometric measurements and NMR spectra show that Scholer molecular oxygen attacks the coordinated ligands without metal-ligand presenta bond rupture. The main product of the reaction is identified as due ReO to oxidation of a C - methyl to a hydroperoxide group. The NMR , and 5.M. experiments suggest that the reaction proceeds until at least three compound: out of the six methyl groups are oxidized. Kinetic measurements show B0^ as e that the reaction is first order with respect to the complex, half have the order with respect to oxygen, and suggest that protonation is involved the C1~ in a pre-equilibrium step. Iron (III) is shown to promote the reaction ra, M. P while iron (II) ions strongly inhibit it. 135 (197 Comparative studies of .related complexes jshov: that the oxidation formulas takes place only when methyl or methylene groups are attached to Ln = La carbon. It is also interesting to point out that the ability of these for all complexes to undergo autoxidation follows their redox potentials. A mechanism is proposed for the autoxidation of tris-(biacetyl- The PO s bismethylimine) iron(II) involvine an intramolecular electron transfer being fu followed by a free-radical chain mechanism. even it Metal-Li 250 cm"1 This work was supported by the Fundac.ao de Amparo a Pesquisa do The elec Estado de Sao Paulo. complexe but some means a coordina spectra

Deceased The gran Estado d afcout a change in spin-type and stereochemistry. Reaction of the Schiff bases (IIIJ with ferric chloride yields the high-spin complexes (PeI][I(ONS) ![Femci ]. and one niti

KMS .9 73

C "NOM COORDINATING" AN IONS, coCOMPLEXEr S OF HEXAMETHYLPHOSPHORAMIDE AND ELECTI LANTHANIDE IONS. c V ~~~OTA. Serra and .CE. Berwerth2 1) Instituto de Qufmica - USP, CP.20780, Sao Paulo, SP, Brasil Helena Li Instituto 2) Instituto de QuTmica - UMESP, CP.174, Araraquara, SP, Brasil

The

Perchlorate anion has been observed coordinated or not to the (c); CH3,C lanthanide ions in hmpa (hexanethylphosphoramide) complexes (R.P. Schoier and A.E. Merbach, Inorg. Chim.Acta, j_5(l), 15 (1975)). In this (j); CH3,C presentation we will relate the properties of the hmpa complexes with acetonitri ReO^, PFg and B0T, anions (some of these prepared by A.B. Mascimento and S.M. Helo, Master's Dissertations - I. Q. -USP, 19 75J_. With B0JJ all The compounds in the serie have the formula JLn(hmpa),(B0«),1 .being the processes BQ~Q as expected not coordinated to the metal ions. The PFJj complexes eleetroche

have the formula [La(hmpa)fi(PF6)3j and [La(hmpa )5C1](PFg)2 (Ln = Pr-Yb), by using c the Cl" is introduzed because^the nethod of preparation used (0.A.Ser- reduction ra, H. Perrier, V.K.Lakatos Osorio and Y.Kawano, Inorg.Chim.Acta, V7» first two 135 (1976)). The ReOT/complexes, present as the Cl0^ complexes two one-electr

formulas: [Ln(hmpa)4(ReO4)2]ReO4 Ln = La - Lu and fLn(hmpa)g](ReO4)3 + e *=* FeL Ln = La - fid, must be noted that for ClO^j, both formula are observed third one- 2 for all elements in the lanthanide serie. Fe(dipy)3 This proce The PO stretching vibration is displaced to low frequency 100 cm" ,

being function of the number of coordinated hmpa and of the anion, The even it is not coordinated; the same influence is observed for the chromophor Metal-Ligand vibration frequencies, that appear between 200 and processes 1 250 cm" . substituen 4 4G 2G for the Nd m The electronic spectra ( I9/2 —•> 5/2 ' 7/2^ ( ) oxidation * complexes with six hmpa molecules are similar at ambient temperature, but some difference arises when the temperature goes to 80°K. This means a influence of the anion in the solid state, even not coordinated to the metal ion. f'ore results of the electronic spectra will be treated in the presentation. Acknowledg Fundacao d Conselho N The grant to one of us (E.C.B.) by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), is gratefully acknowledged. rerrace(.i.L,> mononyarace snows cnat eacn Ligana is Diaencace cnrougn one oxygen a and one nitrogen atom with the three nitrogen atoms lying on an octahedron face.

74 KMS.R.l vV .• , l ELECTROCHEMISTRY AND SPECTRAL PROPERTIES OF IRON DIIMINE COMPLEXES ^ IN ACETONITRILE

Helena Li Chum, Neyde Y. Murakami , and Monica Rock Instituto de Qu£mica, Universidade de Sao Paulo, Brazil.

The electrochemical behavior of the iron(II) diimine complexes, 2+ FeLs , L = H2CN=C(R)-C(R')=NCH3, where R,R' = H,H (a); H,CH3 (b); CH3,CH3

(c); CH3,C2H5 (d); -CH2CH2CH2CH2- (e); -CH2CH(CH3)CH-JCHJ- (f); or L =

C5H5N-C(R1)-NR2 where = H CH (< H C H (h) ; CH CH CH C H Rj ' 3 3> ' ' 2 5 3' 3 (i) > 3' 2 5 (j); CH3,CgH5 (k); C6H5,CH3 (1); C5H5,CgH5 (m) was investigated in acetonitrile, 0.2 M in tetraethylammonium perchlorate.

The electrochemical oxidations are one-electron reversible processes yielding the corresponding stable iron(III) compounds. The electrochemical reductions of some of these compounds were also studied by using cyclic voltammetric and polarographic techniques. Pour to five reduction waves were observed in the accessible potential range. The first two reduction waves are diffusion controlled and correspond to 2 + one-electron reversible processes: FeL3 + e ^ FeL. and FeL. + e *=* FeL.,, where L = a, c, i, n,and g. This last compound exhibits a third one-electron reduction wave, which was also observed for 2+ Fe(dipy)3 (N. Tanaka and Y. Sato, Electrochim. Acta, 12[, 335 (1968) ) . This process and be formally written as FeL, + e «=* FeL,~,

The influence of the groups R, R1 and R-^^ on t^ie diiroine chromophore will be presented. Half-wave potentials for the oxidation processes will be correlated with polar Taft parameters of the organic substituents. The correlation between half-wave potentials for the oxidation processes with the energy of the inverse charge transfer band to —» ir will be discussed.

Acknowledgments: The authors acknowledge financial support from the Funda^io de Amparo a Pesquisa do Estado de Sao Paulo and from the Conselho Nacional de Pesquisas. 1.12 75 SEK.I-EMPIRICAl WO STUDY OP THE ELECTRONIC STRUCTURE AND THE EXCITED STATES OF M. Costast G. Höjer Departamento tie Quimica Teórica, Div, Estudios Sup.de la Pac. de Quimica. U.N.A.M. Cd. Universitaria Mexico 20 D.P. + Escuela Nacional de ^studios -crofesionales (Plantel Zaragoza), U.N.A.M. A modification of the Pariser,Parr and Pople semierapirical method, the PEEL method , has been applied in an investigation of the electronic structure of the ground and excited states of open and closed shell metallocenes of the first transition series. The absorption spectrum is analysed in terms of d-d,CT and pi-pi+ transitions. The results, when posible, are compared with the experimental assigroents in photoionizatio» spectra and with other theoretical calculations. 76 1.13

r LOW-TEMPSRATUR] .v '"Gas Phase Ion-Molecule Reactions of Methylcyclopentadienyl-manganese

The ion cyclotron resonance spectrum of methylcyclopentadienylman- The magnetic p ganese tricarbonyl reveals the formation of 3 main ions by electron were measured impact of 20 to 50 eV of energy: [C,H_)Mn(CO)t (m/e=218), (C.H-JMn(CO)+ to 13.10 kG . • .

Ueff = 3-012 3 •n/e= 162) and (CcH_)Mn (m/e=134). Reaction of these ions with a variety of nitrogen bases at low pressures (ca. 10,- 5~" torr) results Curie behaviou :r. sor.e c^ses in substitution of a CO ligand by the nitrogen base. BM at O.9OK is "hese reactions are used to establish a relative scale of intrinsic the basis of **• iigand stability for the manganese ion, which is independent of Energy Diagram -olvntion effects. states the res Dq=28,5 =67, the optical sp h(a^e^l), 3E For cobaltocer

-,eff = 1.460 B* 1.372 BM at 0. af well as for achieved assun &' =O.J>k and £

(g]| = 1.68, g

D , symmetry ao h S = 74, B = 446 The resulting both systems The rhombic d

for Cr(C5H5). explained on 1.14 77

LOW-TEMPERATURE MAGN3TISM AND THE LIGAND FIELDS IN CHROMOCENE AND COBALTOCENE ON THE ANOMALOUS fi. Schnakig,a B. Kanellakopulos, and R. Klenze0 Institut flir Physikali&che Chemie, University of Erlangen-Niirnberg, P. De Filippo, F D-8520 Erlangen, West Germany DHeisse Chemie, Kernforscr. ungszentrum, D-75OO Karlsruhe, West Germany Istituto Chimicc

The magnetic properties of chrornocene Cr(C,-H_)^ and ;obaltocene Co(C_H,-)2 In the previous] were measured oetween 0.90K and 300K 3t six different field strengths, H =3.50 hamate)±ron(III) to 13.10 kG,. For chromocene , u is almost constant between 300 and~12K low spin state ( This conclusion (ueff =3-012 BM at 303<2K, Ueff =2.^92 BM at 1<.10K), whereas £m approaches viour of dtc and Curie behaviour (w^ = -0.7K). Below 12K, a continuous decrease to u --=1.392 well-known spin P - e 1 i The Fe(dsc1-; dar BM at 0.9OK is observed. A lsast-squares fit of the data was accomplished on stallization to the basis of complete ligand field theory (.E.Kb'nig and S.Kremer, Ligand Field 1ous magnetic mo Energy Diagrams, Plenuai Press ] . Of ail possible triplet ground New York tween QO to 400° statetates the resultres s are reproduced only for S(a^e^) with Dt = 11531 Ds = -4212, te equilibrium. q = 28,£ =67, B = 553, ail in en." C/B = -. and k' =0.3" he unique band in The experimental optical spectrum at .21,900 ?m- 1 is obtained as the transition 3 3 ECae) 2 2 = 0.7 5s + For cobaltocene , \i ~- is slovly aecreasing from u ** = 1.735 BM at 298 .OK to 1 + •* „„ = 1.460 BM at 1'J.35^-1 followed oy almost constant values down to y. -„ = where x = ;/kT 1 .372 BM at O.97K, whereas V';r produces straight lines for T > 20K (9 = -10K) tional partitioi a? well as for T < '4K (0 =0:. The best least-sqaares fit of the data was 2_2 , 2~2 t**+-. . . . i» „_ -1 achieved assuming a E^e^e,; ground state in symmetry,^ = 73 cm" it' =0.34 and a zero-field splitting- d = 12"? cm Experimental EPR data (g., =1.68, gj_=1.75) are .veil reproduced as are tne optical spectra The . and v p 24 -12 - ? * -1 , t s as ("A,(a,e,e,) 17,000 cm ; A.(a"e"e,) 18,300 cm ). Here the assumption of v together wit D . symmetry is sufficient to account for the data and Dt = 2210, 03 = -^ a Fitting progr< 1 These results a] £ = 74, B = 446, C = 2340, all in cm" , and k' =0.34. Fe(dtc) and FeI The resulting ligand field and the equivalent AOM parameters demonstrate that fluence. both systems are comparable with respect to structure and bonding properties. The rhombic distortion is small (Du = 10, Dv = 6 cm for CoCCt-HjJj! Du = Dvas 0 for Cr(CE.H1-)?), whereas the large reduction of £ and k' may be reasonably explained on the basis of a dynamic Jann-Teller effect. 78 1.15

ON THE ANOMALOUS MAGNETIC PROPERTIES OF TRIS(DISELENOCARBAMATE)IRON(III) MECHANISM OF 5 P. De Filippo, P. DepJano, A. Diaz, S. Steffe and E.F. Trogu AND IrH(CO)(PI Istituto Chimico, Universita di CagJiari, Italy. J.A. Carroll, In the previously reported data on magnetic behaviour of tris(diselenocar- Department of Columbia, Cane bamate)iron(lll) this class of compounds was definitely classified in the low spin state (v, values ranging between 1,90-2.36 B.M.). TrC (CO) J'Th,) This conclusion strongly contrasts with the very close spectroscopic beha- viour of dtc and dsc ligands, the first doing iron*III) derivatives with a ______~— .^2 corr.ple:-: ' •' IrC] well-known spin equilibrium between the Aj and T2 states. The Fe(. dsc) •; dark brown compounds prepared by us after a fractionary cry- stallization to eliminate a yellow 1 igand oxidation product, show anoma- ethanol IrCl '.' lous magnetic moments (u ranging between 2.2b-4-9& B.M. for T ranging be- tween 00 to 400°K) which are rationalizable in terms of the same spin sta- the orth?.7ietal te equilibrium. The experimental values was handled by means of the van Vleck's eauation: diaryltetrazen '"r.r.rr. ?oc. Rev O.75g 105 C exp[-(E + - 2exp [-3x/2 "] * 3 C exp ["-(E '•: 3 s TV ,-j ,-tion where x = ;/kT and C is defined as the ratio between the molecular vibra- dttacked by tional partition functions in Aj and T2 states, i.e.: to yield iB)

1-exp ["- fir(NHNR)(CO) C = Q/QT =' R\'? to yield

I'he . and v values have been obtained by an i.r. study while v and .Ti

ions, and chai financial suppoi a Scholarship.

1.16 79

MECHANISM OF SOME REACTIONS OF DIAZONIUM IONS WITH IrCl(CO)(PPh-J, CARBONYL LIGA1 u-H[M(CO)5]2" AND IrH(CO)(PPh3)3 Marcetta Y. D,

J.A. Carroll, N. Farrell and P. Sutton Department of Department of Chemistry, Simon Fraser University, Burnaby, British New Orleans, } Columbia, Canada, V5A 1S6 Studies i liRand (M. Y. ' rC (CO) /->rh,),, reacts with diazonium ions to yield the aryldiazo (1976)C68) ha- apparently pn complex '-'IrCl (CO) (N~R) (PPh,)-} ][BF ] (A; n probably = 2), which to nulti-subsi 4 In the case o: wi-.n Cl~ .jives IrCl (CO'1 C\ R) (PPh,) , (B). However, in benzene- PPh3, a yellow 2 0 Et^ u-H[Mo(( othanol JrCl CO) (PPh,!-, =md diazoniur. ions qive (B) together with of nreparatioi the orth -retaliated complex JlrCl (CO) :\'HNR) (PPh ) ] BF (C) and the Chatt, et al_. 3 4 Shaw and Hui, •iiaryltetrazene complex ! Ir iN^RHCO) (PPh, ' ^ ] BF. (D) iD. Sutton,

• 'r.v.T. So.-:. Rev. 4_, 443 (1975)}. We shall present evidence that

: ;s i-t ,i ;tion involves the initial formation o€ (A) , which is attacked by ethanol to cleave asymmetrically the bridges to yield iB) and a reactive intermediate (E) of the type

fir (NHNR) (CO) (PPh '< ]BF. . Complex (E) than reacts with further

R".'9 to yield the diaryltetrazene complex (D) or undergoes ortho- nv-taliaLion and oxidation, to yield (C) , yjui an intermediate orthometallated arylhydrazido complex [Ir(NHNHR)(CO)(PPh3)2]BF4 (D. The intermediate (F) has been isolated, and has been alternatively synthesized from the reaction of IrH(CO)(PPh3>3 with diazonium ions, and characterised by i.r., n.m.r., and X-ray crystallography. financial support. A.L.B. and G.R.S. thank the Science Research Council for a Scholarship.

80 1.17

Y"''£ CARBONYL LIGAND LABILITY IN THE HYDRIDE BRIDGED BINUCLEAR ANIONS, PLATINUM (0; Ai .V \>'

Studies of the reaction of u-H[M(CO) ] "(M = Cr) witlr^A donor 5 2 Calcrimeti lip.and (M. Y. Darensbourg and N. Walker, J. Organometal. Chem., 1J2 fol iowiiiC t'/'-^c-: (19 76)C68) have been extended to include M = Mo and W. All reactions apparently proceed via a CO dissociative mechanism, ultimately leading to multi-substituted products, L,M(CO) or L M(CO) (L = PR ,AsR ). 4 3 3 3 3 where t:M lioar In the cnse of reaction of Et^N* u-H[Mo(CO) ] ~ in the presence of 5 2 an unsaturatea Prh . a yellow crvstalline solid is obtained which analyses as 3 a.-: prvVX-'usly i Et^ u-H[Mo(CO) ][Mo(CO) PPh ]-. The analogy between this mode ; 1< 3 Acta , -•" -~. of preparation of substituted V1B metal carbonyls and that of Chatt, £t_ al., J. Organometal. Chem., 29(1971)105, as well as that of Shaw and Hui, J. Organometal. Chem., 124(1977)262, will be discussed. .las oeer. noa.-ai which was -':.•= s

This gives the impossible :c vrlatinjir. compov could also CL

II. t.i'.-- IOJ ":'np .ijscve rea~t Ethyler.e weaken? tiie bor different from phenyl groups diphenvlethyler faarlv low ener from ^F . The results: ciF smaller differe T.\ the phc creases the bon substitution gi acetylene (-96. compound. Only somew since in additi and triple bond interferences o of the phenyl g M.A. De Paoli

1.18 //i L'::TF:.": • ::•- "^F sour rcpjiATir:-: BETWEEN-BIO-TRIPHENYL PHOSPHINE OR BIS-TRIPHEMYLARSINE PLATINUM (ii) AND VARIOUS UNSATURATED HYDROCARBONS M.W. Lister and R.B. Poyntz •^ I IDF.NTIFTCATIOJ.

Department of Chemistry, University of Toronto, Toronto, Canada H. Barros and Department of New Orleans, I

Systematj Calonmetric measurements have been made of the enthalpies of reactions of the fol low.r.a ty;.>e : charged trans: either solvent : ,'•••-•. •-• •*- r.u\ .1 • .^<>t.>' 3 (soin) - unisoiti) + [.<.-:• cs./i) n. J. Darensbc where th^. liaa:v: L was either triphenylphosphine or triphenylarsine. Un represents 3127(1976); M. an jnsafurdteu hydrocarbon containing either a double or triple bond. In addition 3121(1976): M. a.- r--r.-vi.udiy reputed (.\\o. Kirkham, M.W. Lister, and R.E. ?-yntz, Thermochim. J. Am. Chem. £ Acts __, -•" 1975) j the enthali • of the reaction these effects reactivity. A t^'xc - .-.CS., ' - L F- 'S.Jsoln) + (n-l)CS,(l) nuclear magnet :ias aee:". r.ca.-area, as I'.a-x . sc the- hea- - of solution of these compounds m benzene, cation-anion i whicn was ::".•= tolve.-t fcr some of the reactions. Some subsidiary studies of the such as [Ph3PN sta:.int'/ . r ::ie compour, -";= , and _.,t rates and completeness of reaction have been (hJ-CrK5)Fe(CC (h5-C5Hs)Fe(CC

-T a re.-ult it is possible to calculate AHC for the reactions:

This g:ves the best available comparison of the bond strengths, since it is impo.-.sible :•: ;j.lculate . •• for the reactions totally in the gas phase, as the i:latir.or, compounds cannot be volatilized. Anaioaous AH° m benzene solution could als-: bi. calculated.

I;, t.i' rollowmg summars' the i.umbers aft--r each hydrocarbon are AH0 for 'ho accve reaction m kJ moxt" -. Ethyler.e (1". .d) does not attach very strongly, and substitution by alkyl groups weaken? the bond in the case of cia-butene (23.2). Cyclic defines are however little different from : cyclopentene (9.5), cyclohexene (14.6). Substitution by phenvi groups greatly increases the stability: phenylethylene (-29.7), cis-1, 2- diphenvlethylene (-78.6), trans 1,2 diphenylethylene (-96.9); these presumably have fairlv low energy ---orbitals that are unfilled, and available for IT back-bonding from,? . The last two compounds were also measured for the arsine system with the results: ci.= (-67.7), trans (-70.5), which, while in the same order, have a much smaller difference.

I:, the phosphine compounds with acetylene derivatives, alkyl substitution in- creases the bond strenath: acetylene (-10.0), 1-butyne (-19.3), 2-butyne (-46.6). Aryl substitution gives results similar to the olefines: phenylacetylene (-64.5), diphenyl- acetylene (-96.0). In the arsine system diphenylacetylene (-160.1) gives a very stable compound.

Only somewhat tentative explanations can be offered for these results at present, since in addition to obvious considerations of electron availability at the double .=ind trxple bond, and the energies of levels available for TI back-bonding, steric interferences of atoms on the various ligands have to be considered, and in the case of the phenyl groups the effect of non-planarity on the TT energy levels. M.A. De Paoli thanks a research fellow from the Hutnboldt Stiftung,

82 1.19 REACTIVITY IN IDENTIFICATION OF ION-PAIR INTERACTIONS IN TRANSITION METAL_ORGANIC SALTS M. L. Maroso, II. Barros and M. Y. Darensbourg Institute of Department of Chemistry, Tulane University C.P. 1170, 13 New Orleans, Louisiana 70118 USA

Systematic attempts to identify and quantifv interactions of charged transition metal carbonyl and ir-complex derivatives with Metal atoms a either solvent or counter-ion have been made (M. Y. Darensbourg, D. J. Darensbourg, D. Burns, and D. Drew, J. Am. Chem. Soc, 98, in S Ar react 3127(1976); M. Y. Darensbourp and C. Borman, Inorg. Chem., 15, p. 94). 3121(1976): M. Y. Darensbourp, C. Bnrman and H. L. C. Barros, .J. Am. Chem. Soc, 99_, (1977)). Discussion will be directed to This pre these effects particularly as thev are related to chemical of chlorobenzi reactivity. A combination of conductivitv, v(C0) infrared, and nuclear magnetic resonance data has been used in defining Our cone! cation-anion interactions in transition metal-organic salts (i) the relai + such as [Ph3PNPPh-+] [HFe(C0)i,-], Nn HFe(CO)u~, Na+ Fe(CO)uCN", 5 5 displace! (h -CrjH5)Fe(CO)2L+ BF4", (h -C5H5)Fe(CO)L?+ BF^ (L = PPh3) and 5 (h -C5Hs)Fe(CO)2(olefin)+ BF4-. "f erroph: the benz (ii) it is nei between metal-orj iii)the - Fe combined creases remarKaniy in Acknowledging Fundaçâo de Army Researc

1.20 83

<; REACTIVITY IN NUCLEOPHILIC SUBSTITUTION OF ARENECYCLOPENTADIENE FERROCENIUM IONS SOME PREPARATIO1 M. L. Maroso, J. Miller and E. J. de Souza Vichi M.M. Singh Institute of Chemistry, Universidade Estadual de Campinas Department C.P. 1170, 13.100 - Campinas - SP BRASIL Diorugarh '

Metal atoms attached to an aromatic ring have been designated as a class of substituents The additie in S Ar reactions (J. Miller, "Aromatic Nucleophilic Substitution", Elsevier 1968, solution oJ P. 94). solid sodii This preliminary investigation reports kinetic studies of nucleophilic substitution carbonylnii of chlorobenzene and p-dichlorobenzene--ferrocenium tetrafluoroborate. Br, I, CN; Our conclusions may be summarised as and non-coi (i) the relative strength of nucleophiles is different from that found normally in strong absc displacement of chlorine in S^r reactions; but is consistent with the view that the presenc "ferrophilic" reagents first attack the metal atom, whereas other reagents attack carbonyl si the benzene ring directly; compounds (ii) it is necessary to discount the favourable entropy of activation of reactions probably di between an anion and a cation, when comparing intrinsic reactivities of cationic acceptor tl metal-organic substrates with neutral aromatic substrates. not only r iii)the - Fe Cpj substituent is strongly activating but considerably less so than the producing combined 2-and 4-N0_ groups of l-chloro-2,4-dinitrobenzene. Further, t crystals o frequencie order Y= interconve remains um presence of Acknowledgment: The authors acknowledge financial support from the Fundagao de Amparo a Pesquisa do Estado de Sao Paulo and the U.S. ty of the s. Army Research Office (Durham) .

84 1.21 SOME C^RBONYLNITROSYL AND NITROSYL COMPOUNDS OF RHODIUM-THEIR C ' SYNTHESIS ANT PREPARATIONS AND I.R. STUDIES. ii M.M. Singh and D. Dowerah A. L. RheitiRc Department of Department of Chemistry, University of Dibrugarh, College of Ar Diorugarh 786004, Assam, India. Ferrocene is X=C1, Br or I The addition of moderately concentrated hydrohalic acids HX to a assisted mecti solution of trans- ^RhCOYLj in oxygen free chloroform containing Cp2FeEX4. Th of irregular solid sodium nitrite produces a series of brown crystalline Mamma no, A « Z carbonylnitrosyl derivatives of the type (fRhCOYNOXL^)'where X=C1, The various t Br, I, CN; L=PPh3', AsPh3 and Y= Cl, Br and T." They are diamagnetic prior to oxid and non-conducting in nonaqueous solvents. These compounds exhibit in which pery Baughan, J. C strong absorption bands at *<*• 1630cm~ and at 2100 cm indicating the presence of nitrosyl and carbonyl groups in them. The shift of 2Cp carbonyl stretching frequency from 1S60-1980 cm" region for parent All ferroceni are water sol compounds to —^ 2100cm for the nitrosylcarbonyl derivatives is data obtained probably due to the presence of nitrosyl group which is a better 7T of these data

acceptor than carbonyl group. The action ojf_ AgNO3 on [RhCOYNOXL^ Organodihalop not only removes the halide ions but also expels the CO group Cp2FeREX3; cr organopnic tid Rh(NO)(NOj)2L2J-

Further, the action ofhalogen^on ['Rh (NO) (NO3)2 L^j yields brown

crystals of the type IRh(NO)Y~L0j where nitrosyl stretching —1 —1 frequencies shift gradually from 1650cm to 1620cm in the order Y= NO3^ Cl > Br>I. It is curious to note that in these interconversions the formal oxidation state of rhodium apparently remains unchanged. presence of labile high-spin form was also confirmed by EPR measurements. The intensj. ty of the signal with a g-1.950 was shown to be temperature-dependent. Decei

1.22 85

* A, SYNTHESIS c/SYNTHESIS AND CHARACTERIZATION OF FERROCENIUM TETRAHALOPNICTIDES if G. Schmid an i A. L. Rheingold, M, F. El-Shazley, and N. J. Mammano Department of Chemistry, State University of New York Department o College of Arts and Science, Plattsburgh, New York 12901 (USA)

H Ferrocene is oxidized by a combination of a group-V trihalide, EX3 (E=>\s, Sb or Bi; A -l,3,2-dia X=C1, Br or I) and molecular oxygen in suitable solvents by a photolytically assisted mechanism to form structually varied products of the general formula Cp2FeEX^. The tetrahalopnictide ion in Cp-jFeBiCl^ is a novel extended structure of irregular BiClg octahedra joined along edges by halogen bridges. (N. J. Mammano, A. Zalkin, A. Landers and A. L. Rheingold, Inorg. Chem.,in press.)

The various trihalopnictides all appear to form a common intermediate, (Cp2FeEX2) , prior to oxidation to the ferrocenium ion. This is well characterized in reactions in which perylene or phenanthrene replaces ferrocene. (P. V. Johnson and E. C, Baughan, J. Chem. Soc. A, 2686 (1969)). The overall reaction can be written as are isoelect to be good c 2Cp2Fe + 3EX3 + 1/2 02 •• 2Cp2FeEX4 EOX 1,3-di-tert- All ferrocenium ion salts prepared to date are stable in air, melt above 300°, are water soluble, but are slowly converted in water to Cp2FeFeX^. Kinetic data obtained by ESR and UV .spectroscopic techniques and the mechanistic implications of these data for the conversion to the tetrahaloferrate salts will be presented.

Organodihalopnictides, REX2 (R = alkyl or aryl), also form the related products Cp2FeEEX.j; crystallographic structure determinations are in progress for the organopnictide derivatives.

by reaction The yellow are soluble peak at m/e be observed, atom better data the H C=C-douKLe b downfield, a are also in reactions wi Deceased The gran Estado d

86 1.23

,A, SYNTHESIS AND PROPERTIES OF iu"l,3,

Department of Chemistry, University of Marburg, BRD Department (U.P.) , Ir A*-l,3,2-diazaborolines So of "*) -cyclo

1A* 173 (19 at 120°C in In

are isoelectronir- with the cyclopenLadieny 1 anion CrH_ ;jnd therefore thought complexes, »4 .,5 to be good complex ligaru'-. Wit'i - R" = CI.CH j , R" » CH and R = R" = H the when a slow 2-mut.hy I -'•'*- , 3, 2-diaza..'>"-(•) 1 in uld bo used as ligand in reacted wit (ii = P, As Transition

analyses ar The carbonj given (Tab] (CH3)3C

by reaction of (CH-CN).Cr(CO)- with the diazaboroline in dioxane at 859C. The yellow crystals can be isolated in 91% yield. They decompose at 1709C and are soluble in inert organic solvents. The mass spectrum shows the molecule

peak at ra/e = 330. In the i.r. spectrum two J)CO bands at 1929 and 1831 cm can C») -C5H5)* be observed. The B-signal at 18,3 ppm (downfield from BF^.OEt,) shows the B . 11 atom better shielded than in the free ring (26 ppm). In agreement with the B [(V -c.ti. data the H n.m.r. spectrum shows a high field shift for the protons of the C=C-double bond, whereas the H signals of the C(CH,)_ groups are shifted 13 downfield, as the nitrogen atoms serve as donor atoms. C n.m.r. investigations are also in accord with the other data mentioned above. It will be reported on reactions with other metal groups like Mo(CO) , W(CO), of C HJn. spectra wi i i ue treated in tue Fundagao d< Conselho N« The grant to one of us (E.C.R.) by Fundagao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), is gratefully acknowledged.

* 1.24 87

SYNTH3SIS OF V -CYCLOPENTADIENYLIRON NITROSYL COMPLEXES CONTAINING ^ (HYDROLYSIS OF GROUP VA DONORS E. Mendelovic V. N. Pandey Department of Chemistry, University of G-orakhpur, Gorakhpur-273001 Instituto Ven (U.P.) , India. and Instituto No attention has been paid so far to the nitrosyl chemistry The reac of i) -cyclopentadienyliron carbonyl derivatives. Only one compound fibrous two 1 [( "*) -CcH|-)Fe(N0)3 p kas been prepared ( H. Brunner, J. Organomet. Chem., reported (E. 1£, 173 (1968) ) from the reaction of \j ^-CgH^PefCO)^ with NO vici, Bull. S at 12O°C in alkanes. diphenyldichl In the present paper I report the syntheses of new nitrosyl have been hyd nd Beside, attap complexes. £(*>) -C5H5)Fe(NO) (CoJ2 * (?) -C5H5)Fe(NO)(CO)I are formed when a slow stream of NO is passed through a benzene solution of tetrahedons a Al and Mg ato 1(1?-<^cH(.)?e(CO)^]2 and C»?-C5H5)Fe(CO)2I respectively. Similarly NO alkoxysilanes reacted with (i) -C5H5)Pe(CO) (Ph^EjI and [( >) -C5H5)Fe(CO) 2C2h^&)] I (H = P, As and Sb) (£. C. Tripathi, S. C. Srivastava and V. N. Pandey, An infr£ the reaction Transition Met. Chem., in press) to give ("*) -C5Hc)Pe(NO)(Ph5E)I and mainly at 30f [_C9 -C5Hc)Pe(NO)2(Ph5£)]l respectively. Satisfactory elemental 1 analyses and infrared spectra have been obtained for these derivatives. 780 cm" . Th The carbonyl and nitrosyl stretching frequencies of the complexes are absorptions given (Table). Moreover, fre attributed t( Table Me2Ph-Si-O-3i -1 -1 cm (NO) cm difunctional

In the [(7?-C5H5)Fe(NO)(GOJ]2 2050 s, 2000 m 1550 - 1600 s (vbr) be hydrolyzed C9 -C H )Pe(NC)(CO)I 2025 s 1650 s 5 5 DMDES undergo 1660 vs low molecular 1662 vs in the oil se In absen (**) -C H )? 1661 VB 5 5 3 reaction was

[CO -C5ii5)Fe(NO)2(Ph3P)]l 1724 m, 1633 s the one previ 1725 m, 1640 s the covalent reacting orga 1724 m, 1638 s The hydr iluminosilicat Fundacao de Amparo a Pesquisa do Estado de Sao Paulo and from the Conselho Nacional de Pesquisas.

!<•• ' 88 1.25

OF ORGANOSILICON COMPOUNDS IN THE PRESENCE OF SOME ALUMIN0SIL1CATES.

E. Mendelovici

Instituto Venezolano de Investigaciones Cientificas, Apdo. 1827, Caracas, Venezuela and Instituto de Investigacion Quimica, U.L.A., Merida. The reaction of methyl and vinyl chlorosilanes with chrysotile-asbestos ( a fibrous two layer type trioctahedral silicate) in acid medium has been previously reported (E. Mendelovici, Th. Doct. Sc. Louvain, 1967) and (J.J. Fripiat et E. Mendelo- vici, Bull. Soc. Chim. 2, 483-492, 1968). In this work, phenyltrichlorosilane, diphenyldichlorosilane, Tnethylphenyldichlorosilane and dimethylphenylclorosilane have been hydrolized by HC1 diluted to 6N with isopropanol in the presence of chrysotile. Beside, attapulgite (a 3 laver structure type mineral, where chains of silica tetrahedor.s are linked together by octahedral groups of oxygens and OH containing Al and Mg atoms in hexahedral coordination) has been refluxed with difunction:l alkoxysilanes such as diphenyldiethoxysilane and dimethyldiethoxysilane (DMDES). An infrared absorption study of the acid hydrolyzed fractions, separated from the reaction mixtures, shows the appearence of frequencies due to the Si-Ph vibrations mainly at 3055, 3075, 3020, 1590, 1430, 995cm and a triplet in the range 694 to 780 cm . The spectrum of the hydrolysis product of MejPhSiCl is characterized also by absorptions due to the methyl groups, mainly at 2960, 1260, 840 and 800 cm" . Moreover, frequencies at 1000 and 472 cm observed on the same spectrum and attributed to Si-O-Si vibrations suggest the formation of a siloxanic compound:

Me2Ph-Si-O-3iPhl-ie2. A comparative study of the acid hydrolysis of the mentioned difunctional organosilanes is further discussed. In the presence of attapulgite, it is interesting to point out that DMDES may be hydrolyzed whether HC1 intervenes or not in the reaction. In the first case DMDES undergoes a classical hydrolysis in strongly acid medium yielding cyclic or low molecular weight polymers. Polydimethylsiloxane was identifies by i.r. spectroscopy in the oil separated from the reaction mixture as well as in the modified mineral. In absence of HC1, DMDES is hydrolyzed by HjO contained in attapulgite (the reaction was carried out in anhydrous benzene medium) by a different mechanism than the one previously described. Then, more stable organomineral compounds were formed upon the covalent grafting in the silicates of organosiloxy units, arising from the reacting organosilanes. The hydrolytic capacity shown by attapulgite is not common to all the iluminosilicates and will be further commented. I.R.3 89

CHLOROMERCURIOLACTONIZATION OF ALLYLALKYLBARBITURIC ACIDS. L. do Amaral, O.A. El Seoud, and R. Moscovici. Instituto de Qulmica da Universidade de Sao Paulo - Caixa Postal 20780, REACTION Sao Paulo, SP, Brasil. METAL CO

The chloromercuriation of v,5-unsaturated carboxylic acids, CBiran, and their , has been studied by R.L. Rowland et al. (J.Amer.Chem. Istituto

Soc, 23, 371 (1951), and by L. do Amaral et al. (J.Org.Chem., 3^, 1951 The carb (1974): ibid., 40, 2534 (1975). of early In this work the chloromercuriolactonization of 5-allyl-5- the Mcp_ into dif -isobutylbarbituric acid was carried out by treating an aqueous solution riani, J of the sodium salt of the acid with mercuric chloride, at roan temperature. therein! vity of J.C.S.Ch +HgCl pentadie CH2=CH-CH2 CH2-CH(CH3)2 — -* Cl-Hg-CH2-CH-CH2 carbodii 5- >( into the . 0-C O - c=o giving, *-H s/" in the f such iis nates. chemical The 6-chloromercuriomethyl-4a-isobutyl-2,4-dioxo-5,6-di- induced hydrofurano {b,e} pyrimidine was obtained with a yield of 76%, m.p. products xes (I) 250°C. It has been identified by elemental analysis (Ccalc 31.16, chemical Cfound 31-38> Hcalc 3'54' "found 3'68} Ncalc 6'61' Nfound 6'61) and (II), to

by its H NMR spectrum in pyridine-d5 (6, p.p.m., 0.07, 3H; 0.13, 3H; cleavage 0.97, 1 H; 1.39, 2 H; 2.09, 2 H; ?.47, 2 H; 3.OS, 1 H) . 90 I.R.4 CYCLIC

REACTIONS OP WITH CARBENE-LIKE BISCYCLOPENTADIENYL Helena I METAL COMPLEXES. (1) Inst (2) Depa C.Biran, G.Pachinetti and C.Floriani de E Istituto di Chimica Generale, Universita di Pisa, Italy. (3) Chen 5322

The carbenoid reactivity of many biscyclopentadienyl derivatives of early transition metals is widely proved by the addition of derivati

the Mcp2 (cp = ^-C5H5) unit to multiple bonds or from its insertion (salen),

into different covalent bonds. FcFachinetti, S.Del Nero and C.Flo- CH2Clt C riani, J.C.S.Dalton, 203 and 1046 (1976); idem 2433 (1974) and refs therein"]. In this context we investigated the carbene-like reacti- tetraeth vity of cp2M(CO)2 (M=Ti,Zr) [G.Fachinetti, G.Fochi and C.Floriani, were a p

J.C.S.Chem.Commun., 230, 1976], cp2V and the VI group's biscyclo- behavior pentadienyls towards ketenes, isocyanates, , F carbodiimides and carbon . The reactions resulted either a one-e into the addition of the Mcp~ unit to the unsaturated system rates. F giving, e.g., the corresponding cp_M (ketene) complexes, (I), or slowed d in the formation of Rmononuclear and dinuclear ureylene complexes, by a che ? product. such ^s cp2Ti-N-CO-N-Ticp2 , (II)# from the reaction with isocya- F nates. The reactivity study shows a dramatic change on the chemical behaviour of the coordinated organic moiety. The metal it is no induced formation of nitrenes is evident from the nature of the chemical products formed during the reaction with isocyanates. For comple- F xes (I) the C=C cleavage was observed under mild conditions. The a prono chemical and X-ray structural features of complexes like (I) and linear c (II), together with the general problem of the N=C and C=C bond paramete cleavage induced by transition metal complexes will be stressed. benzyl g indicate as sugge

Acknowle Iho Naci Academy o Sao Paulo ( 11.12 91

\j /CYCLIC VOLTAMMETRY OF ALKYL AND ARYL DERIVATIVES OF BIS(SALICILALDEHYDE)- / ETHYLENEDIIMINECOBALT(III) IN DIMETHYLFORMAMIDE .f, 1 ? 3 1 Helena Li Chum , A.V. Benedetti", E.R. Dockal , and T. Rabockai^ (1) Instituto de Quimica, Universidade de Sâo Paulo,^Sâo Paulo, Brazil; (2) Departamento de Quîmica, Faculdade de Ciências Médioas e Biologicas de Botucatu, Sâo Paulo, Brazil; (3) Chemistry Department, Marquette University, Milwaukee, Wisconsin 53233, USA.

The electrochemical oxidation of fourteen organocobalt(III) derivatives o1f the equatorial ligand bis(salicilaldehyde)ethylenediimine (salen), RCVo (salen)DMF, where R = CH,, n-C3H7, n-C4H9,

GH2C1, C6H5, C6H5CH2, p-CH3C6H4CH2, p-NO2CgH4CH2, c-CgHj^CH^ i-C3H?,

S-C4HQ, and c-CgH.,, was studied in dimethylformamide (DMF), 0.1 M in tetraethylammonium perchlorate. The working and reference electrodes were a platinum and a Ag/AgCl(NaCl) respectively. The electrochemical behavior was studied as a function of the temperature. For the first eleven derivatives above-mentioned at room temperature a one-electron reversible process was observed for fast potential scan rates. For scan rates highter than 50 Vs the electron transfer rate is slowed down. For slow scan rates the electrochemical reaction is followed by a chemical reaction, a solvent-assisted dissociation of the oxicized product.

For the derivatives with secondary alkyl groups at room temperature it is not possible to observe a cathodic peak current due to a very fast chemical reaction. At -20°C the same behavior described above is observed. For the compounds in which the axial organic groups do not exhibit a pronounced steric or mesomeric effect, it is possible to obtain a linear correlation between the half-wave potentials and Taft polar parameters. It is interesting to point out that p-substitution on the benzyl group does not affect the half-wave potentials. These results may indicate that the dominant one-electron oxidized form is RCoV(salen)DMF, as suggested by Vol'pin et al. (J.Chem.Soc.Chem. Comm., 469 (1975)).

Acknowledgment: The authors acknowledge financial support from the Conse- lho Nacional de Pesquisas, the National Science Foundation, the National Academy of Sciences, and the Fundaçâo de Amparo à Pesquisa do Estado de Säo Paulo. 1

92 11.13

Qualitative and quantitative information on the mechanism of the photolysis of the uranyl carboxylic acid/carboxylate system in acidic aqueous solution.

A.G. Brits and R. van Sldik

Department of Chemistry, Potchefstroom University for C.H.E., Potchefstroom 2520, South Africa.

A new approach has been adopted to gain information on the inti= mate mechanism of the photolysis of uranyl carboxylic acid/car= boxylate systems. Data obtained according to polarographic, spectrophotometric and radiochemical procedures reveal qualita= tive and quantitative tendencies which will be reported and discussed. RuB-

The photochemistry of the uranyl oxalic acid/bioxalate/oxalate system has been studied in detail and the results will be dis= cussed in reference to literature data. Other carboxylic acids presently under investigation are formic, acetic and , and the available information will be reported.

Although much has been said about these systems in the past, oiany questions remain unanswered, the proposed reaction me= chanisms do not fit all the experimental observations and the systems are more complex than is generally believed. (A'

11.14 93 • V " * ELECTRON TRANSFER QUENCHING OF METAL COMPLEX EXCITED STATES '•£• R, C. Young, J. Nagle, and T. J. Meyer Department of Chemistry, The University of North Carolina, Chapel Hill, North Carolina 27514, U.S.A.

2+ Electron transfer quenching of the CT excited states of Ru(bpy)3 and related 2+* complexes have been studied by flash photolysis. For example, Ru(bpy)3 can be both oxidatively and reductively quenched as shown by the apoearance of redox products following flash photolysis in the presence of ootential redox quenchers. Recent work has shown the following: 1) In the presence of an appropriate series of redox 2+* reagents, secondary reactions can be driven photochemically; RuBj + Me2NPh •• (L =

+ 2+ RuB3 Me2NPh , RuB 2) Non- or weakly emitting excited states can be captured by electron transfer at high quencher concentrations; trans * - - 3+ - »-«»\# \ + T Ru(TPP)(py)2 + Ru(NH3)g - Ru(TPP)(py)2 + Ru(NH3)6' (TPP is tetraphenyl- O+it porDhine). 3) Disproportionate of RuB- can be chemically catalyzed, + 3+ 2RuB3 ->• RuB3 +. RuB3 . 4) The rates of back electron transfer measured

by flash photolysis following quenching can be extraordinarily rapid, e.g.,

+ for [Ru(bpy)2(CN)2] + Me-N^T -+ [Ru(bpy)2(CN)2]

indicating that long-range electron transfer may occur.

V & 94 11.15

QUENCHING OF THE LUMINESCENT EXCITED STATE OF Ru(bipy) 2+ WITH PENTAAMINECOBALT(III) COMPLEXES 3 Kenneth R. Leopold and Albert Haim

Department of Chemistry, State University of New York, Stony Brook, NY, 11794, U.S.A. In the chemical mechanism for thermal electron transfer between metal complexes, it is postulated that an electron from the reductant is accepted in an orbital of a ligand in the coordination sphere of the oxidant. Direct experimental evidence tor this mechanism comes from a limited number of thermal and pulse radiolysis studies. In the present work, an attempt is made to utilize the high reactivity of excited Ru(bipy)-2+ to generate radical ions in the coordination sphere of metal complexes.

2+ n+ The quenching of the luminescence of *Ru(bipy)3 by Co(NH3)5L complexes

trans has been studied at a doncr concentration ^5x10" M, quencher concentrations 1x10-2x10 M, pH 5.8 and ionic strength 0.10 M. Parallel quenching measurements have also been carried out with the free ligancls. The ruthenium complex was excited with 450 nm radiation and emission intensities were measured at 5§0 nm. oStern-Volmeg nlots yielded quenching rate constants 1.8x103, 6.3x108, 2.0x10/, lxlCr and 2.2x10* M':sec I for the Co(III) complexes in the order given above. Quenching by the free ligands was observed only for \r CH=CH s - sec j and C—». \i )— \ [k ^9x11) M (k 4.3xlO9 M'1 sec-11). 2+ In accord with previous interpretations for quenching of *Ru(bipy)3 by metal complexes and by reducible organic substrates, we postulate the electron transfer reaction

2+ n+ 3+ 15 *Ru(bipy)3 + Co(NH3)5L + Ru(bipy)3 + CofNHj^L^" . Two detailed pathways can be considered for this outer-sphere reaction: electron transfer to the bound ligand or direct reduction of the cobalt(III) center. Flash photolysis measurements aimed at detecting bound radical ion intermediates are in progress and may help distinguish between the alternative mechanisms. f - if' 11.16 95

. JPHOTOCHEMISTR7 Y OF COORDINATIOK COMPOUNDS : NSW PHOTOCHEMICAL PATHWAY TO OLEFIN ,Y./ METATHESIS ?.K:-;AUSZ and F.3ARNIEH Laboratoire de Chimie Organique Thysique, Universite de PARIS VII 1 rue Guy de la Brosse "..: :3 7W> "•';•.-i

The photochemical activation (7\ = 3 v" n.,. of tungsten hexacarbonyl W(CO)g in 0C1. leads to an active specie? , '/hich iias been characterized by its IR and UV absorption spectrum, ^and assume'! tc be .v'(CO) Cl. ( ''.Krausz, r'.Garnier and J.E.Dubois, J.Am.Chem.Soc.^7,^37 (i1?1*). Olefins in presence of •<•''.' .:' anderoo a metathesis reaction

2 EtCflaaCHMs '3tCHSaCHEt

vi'.ich, in contrast to ciassica- .i.etatnesis systems,

- needs no cocatalyot ('avis oc'.d , generally used for the activation of the transition ..iet?.": zo lex catalyst, - exhibits a very hiaii selectivicy , over 99 per cent • and stereospeci- ficity ( trans olefir. .ivin: sbout 100« trans products at o% conversion ) "he thermodynamic and photochemical characteristics of this new metathetic system underline its interest for the approach of the up to now discussed reac- tion mechanism of olefin metathesis. V 96 11.17

COORDINATION COMPOUNDS AND THEIR PHOTOCHEMICAL ACTIVATION IN HOMOGENEOUS CATALYSIS. W.Strohmeier, G.Csontos, L.Weigelt, H. Steigerwald^ K.Grtinter

Department of Physikalische Chemie, University of Wurzburg, Marcusstrafie 9-11 R. D-8700 Wiirzburg, West Germany Investigations on reaction mechanisms of homogeneous catalytical hydrogenations with coordination compounds as catalysts revealed, that the active moiety is an intermediate compound, formed under reaction conditions , and present in a steady state concentration. If activity a (mMol product/mMol catalyst- min) of catalyst should be increased the steady state concentration of this active moiety must be increased. This is possible by a weak UV irradiation. In photochemically supported catalysis three tyoes of reactions were observed: photoactivated, photo- induced and photoreactivated mechanism. With a given substrate photoactivation depends strongly on the proper choice of the ligands in the coordination compound. The quantum flux $, necessary in photochemically supported catalysis depends on the type of the reaction, g) is very low in photoinduced reaction, and in photo- activated reaction activity a of catalyst is proportional to (/Tup to a plateau level.

In photoactivated and photoinduced homogeneous hydrogenation extremely high selectives were observed. Mean activities up to a = 200 and turnover numbers TO up to 100. 000 could be adjusted. ..«"-•

II.R.2 97

Some remarks on the kinetics and mechanisms of anation reactions of Co(III) and Rh(III) ammine complexes by carboxylic acids/car= boxylate ions in acidic aqueous solution.

R. van Eldik

Department of Chemistry, Potchefstroom University for C.H.E., Potchefstroom 2520, South Africa.

In the introductory section of this paper, a short review will be given on the present state of kinetic and mechanistic infor= mation on the anation reactions of Co(III) and Rh(III) ammine complexes by carboxylic acids and carboxylate ions in aqueous solution. Some interesting observed tendencies in the diffe= rent proposed reaction mechanisms and in the values of the rate and activation parameters, will be discussed in detail.

Tht. conclusions drawn from these tendencies serve as a basis for various investigations presently undertaken and of which the available results will be reported and discussed.

The prime object is, to determine whether the process is as= sociative or dissociative,to point out the interrelation of the ion pair formation constant and the interchange rate con= stant when both are determined kinetically and to emphasize certain unexpected similarities in the studied systems. 98 11.18 LINKAGE ISOMERISM OP THE BENZENESELENINATO IONS BY REACTION OP THEIR COBALT(II) AND NICKEL(II) COMPLEXES WITH BIDENTATE NITROGEN DONOR LIGANDS C.Preti and G.Tosi Istituto di Chimica Generale ed Inorgamca, University of Modena, 41100 Modena (Italy) The unknow pseudo-octahedral configurated bis(benzeneseleninato-O) bis(2,2'-bipyridil) and bis(benzeneseleninato-0)bis(1,10-phenantroline) compounds of cobalt(II) and nickel(II) were obtained by reaction in re- fluxing ethanol of the complexes [M(H20)2(X-PhSe02)2] (M= Co, Ni; X= H, p-CI, m-Cl, p-Br, m-Br, p-CH3, p-N02). All the diaquo complexes, of the type seleninato-0,01, react with two mcles of the nitrogen ligands according to the equation 80° [M(H20)2(X-PhSe02)2] + 2L [M(L)2(X-PhSe02)2] + 2H20 (I) to form seleninato-0 type complexes. The newly prepared compounds have been characterized as high-spin and octahedral on the basis of electronic spectra and magnetic measu- rements. Prom far and near infrared spectra the nitrogen donor ligands resulted bidentate chelating and the areneseleninato ions monodentate seleninato-O. The i.r. results agree very well with the conclusions from the e- lectronic spectra; the complexes show, in fact, Dq values that are in keeping with the proposed structures and match with the literature da- ta for CoN402 and NiN402 chromophores. We can conclude that as consequence of the reaction (I), the split off of the water by the nitrogen donor ligands is accompanied by a re-orientation of the bonding of the RSeO2 groups. (V t/ .19 99 -lu

MECHANISM CF REPIACEMNTS IN PENTAC-.ANO(LIGftND)FEF!RATE(II) IONS S. Asperger, I. Murati, D. Pavlovic and A. Sustra Department of Chemistry, Faculty of Pharmacy and Biochemistry, University of Zagreb, P.O. Box 156, 41001 Zagreb, Yugoslavia The kinetics of replacements in pentacyano(ligand)ferrate(II) ions have been extensively studied. Limiting reaction rates, at sufficiently large concen- trations of entering ligand V, have been observed v.lth all the leaving ligands X studied, except water, where the replacements obey the second-order rate law. Both the D and I, itechan.iSTOP can equally well explain all these data. The ap- plication of the steady-state approxiir.ation to the hypothetical intermediates

Fe(CN)g ~ (D mechanism) and Fe(CN)^OH2 ~ (1^ mechanism) , respectively, will give the same observed rate constants for both medianisms (eqs.(1) and (2)), which makes .ut difficult to distinguish them:

(1) v (2) k2[Y] obs.~

Ik,, k and k', k' are rate constants of formation and its reverse for the 3~ 3— 5 internee iates Fe(CN)s and Fe(CW)5l'C , respectively, whereas k» and k' relate tc the formation of the Fe I(CN)_Y fran these intermediates). The only evidence available so far for distinguishing the two mechanisms in this system was recently published (CPavloviC, D.Sutic, and S.Asperger, J.C.S. Dalton, 2406 (1976)), and supports the I, mechanism. We sought further evidence for the I, mechanism by studying the replacement reaction when >: = 3-cyanopyridine, and Y = pyridine, in aqueous solutions containing sorbitol (up to 70?) and glycerol (up to 81%), respectively. When Y is in excess of X, eq. (2) reduces to k^L = k.' [HjC^. Indeed the rate constant decreased linearly with decrease of water concentration in case of added sorbitol, and almost linearly, when glycerol was added. At low water concentration, achieved by addition of sorbitol or glycerol, the rate of replacement (at 25 C) is practically zero due to the very low activity of water. These results strongly support the I, mechanism and make the D mechanism very unlikely. 100 11.20

^"OBSERVATIONS ON THE AQUATION OF COORDINATED PHOSPHITES IN 2+ ' trans- JRu(NH3>4 P(OR2>3] , or R2>, COMPLEXES". DOUGLAS W. FRANCO Depto de Qulmica, F.F.C.L.R.P. da U.S.P., Campus de Ribeirao Preto, Ribeirao Preto, 14100, S.P., BRAZIL.

As a part of a systematic approach to the understanding of the basic

chemistry of phosphites as ligands the compounds trans-|Ru{NH3)4 P(0Et)3

P(OR),2 (TFMS)2, (Raroethyl, isopropyl, butyl and phennyl), and trans-

Ru(NH3)4 (P(OR)3)2] (TFMS)2 have been prepared. These complexes were characterized by ultra-violet and infrared spec- tra, cyclic voltammetry and micro analysis data.

Both series of compounds aguates yelding in each system only one defi ned monophosphite complex as product. The reaction follow the rate law: 2+ d [RU(NH3)4P{OR1)3(H20)] K [RU(NH3)4P(OR1)3P(OR2)3] , (R-j^R-j or dt

R1=R2>

The data obtained are in agreement with the mechanism proposed for 2+ the aquation of the trans- [Ru(NH3)4 (P (OEt)3 ) J ion, (H.TAUBE, D.W.FRANCO, results to be published). Attempts to correlate the nature of the phosphites coordinated with the rate of the aquation of the second phosphite, in trans position to it, is done.

* The author is greathy indebted to F.A.P.E.S.P. for ..financial support.

oo-x llv 11.21 '- .c-r'^C 101 \ jLIGAND-ï/ATHR INT3RAÜT10N EP^J.'jf-j^ïI TTID KIÜJTIOS O? IKIXE RELJ2ASE A COMPARIE /PROL: ?£]•;': >.CYAM0Ai.iiKS?saxui.T3(II) 30;... '.:v..:3. N.JE.Katz, I.«A«Blesa, J'.A.Olabe and '.''.J .Ayraonino. OF ESCA

Oätedra de vjufmica Incrgànica. i'^oul JAÛ de Jiencias xixactas. Universidad C. Battisi Naoicnal de La Plata. 47 es mina 1L5• La Plata, •tepdblica Argentina. The rate constants it, i'or i»e processesÎ Labora tori ,11-. .. / ,..,. 3- T(3-n) + Istituto d

were measured in an efrort tc olucir.ite the kinetic behaviour of the On ca

pentacyanoferrate(II) moiety bcndea ',o alii-hatic nonnaMines and (termi- th«3 molecu nal) diamines. M. Bossa, v/here R— •i'itîiin t.ie tv/o aeries ci' .i?.i•• .•ncnoar^inos: I"î:ïl:2' (1973) 355 , 'vvitn :'. = 0 tc 3. no cor- ligands an rel.iticn was ••"ounc between 1er of f"e ccrr iopondiri.^ oon- binding en v 0UiS:'te :.ioids cf t.-ie lijando. , / rx M?n of t.ie values cT k. (at 25°C) di t.hiocarb r a:- ' t..e no «ivasicn yirani-tori. .'" i.: ' ^ o .'lave beer, interjireted taking b.e. varia i i J^ "c ~ ao ':ur.t tie cent "•ib -.ii;r. : z .••• :;-lva~ion of t'.ie leaving li^and to of' the mol the :.;c -, : va Lien process. with an o j In tae series of .»ifïiirxSa: 9) liK2 (n = 2 to 6), trie rate Tt ca ocna-.vr.t3 were measured at dif "Tarenu pi values in c cder to oompars the ligand cau . rate of release of the neutral li.Tand to that of the menoprotonated one» charge. In 1 The latber -.vas larger, t.-ie ratio k,(!+)/k,(L) decreasing monotonously goinjt from fror, a value of 2 for ethylenediamine to a -value of 1.3 for hexamethyle- the N and nedianine. The activation parameters ^H and ^3 for the release of of coordin L+ seemed to be, in general, smaller fc.aan those for L, although the dif- only one o ferences were always between the limits of error. The results were in- atoms of t terpreted by comparing the changes expected in the structure of water a complete brougnt about by the activa bien processes. The slight sensitivity of The differ k, to the basicity of the ligands allowed the detection of such solvent compounds effects. of oxygen MICROCOPY RtSOLUHON 1 LSI CHAM

102 II.R.3 4'-; A COMPARISON BETWEEN M0N0THI0- AND DITHIOCARBAZATES BY MEANS OF ESCA

C. Battistoni, V. Di Castro and G. Mattogno

Laboratorio di Teoria e Struttura Elett.ronica del CNR, Roma (Italy) Istituto di Chimica Generate, Universita di Roma (Italyx

On continuing our studies on the electronic structure of the molecules RR'NNR"CSX (where X=S or 0) (C. Ba ttisto-ii, M. Bossa, C. Furlani and G. Mattogno, J. Electr. Spectr., 2 (1973) 355), we report the ESCA spectra of some monothiccarbazato lisands and their corresponding Ni(IIl complexes. The obtained binding energy values have been compared with those of the dithiocarbazato compounds with the aim of correlating the b.e. variations with the changes in the electronic structure of the molecules caused by the subsitut ion of one sulpfur atom with an oxygen atom. Tt can be s*-;own that the introduction of an oxygen in the ligand causes a decrease in the Jeloca1ization of th«s electronic charge. Indeed, while the 01s b.e.'s are roughly the same on going from the free ligands to the corresponding complexes, the N and S atoms undergo a net charge increase as a consequence jf coordination. In the similar dithiocarbazato compounds only one of the two S atoms ie coordinated, whilst both S atoms of the CSS group have the same b.i. values, indicting a complete charge delocaliza tion bst'vesn th«? tw. The difference between the monothio- and the dithiocarbazito compounds may bs rsioribsc' to the greater 'icctronegpti*ri"-.y of oxygen compareci to that of the sulphur a':oni. 11.22 103 c ^ J* SUBSTITUTI '/ FOR THE EX SYSTEMATIC STUDIES ON O.S. ELECTRON TRANSFER REACTIONS BETWEEN / CODIrPhen* COBALT(III) AND IRON(II) COMPLEXES. W.J. Louw L.A.A.. Cli veira2, (I.E. Toma1 and C. Giesbrecht1 National C 1) Instituto de QuTmica, I'SP - CP.20780, Sao Paulo, Brasil South Afri 2) Instituto de QuTrHca de Araraquara, UNESP, Sao Paulo, Brasil l'he reactii COUIrphei COD = cvi The highly charged reactants of opposite charge, phen = 1, en = e i + Co(MH,)gdmso and Fe(CN)5L , where dmso = dimethyl sulfoxide and •; = I, L = NHj, iridazole, pyridine, isonicotinamide, pyrazine and ha . been i 7 pyrazinarn de, were used for a systematic invest! nation on the '^t t hose cc limiting rates of .o_uter sphere electron transfer reactions. CODtrphen According to the proposed mechanisr,

3+ 3 Co(NH3)5dmso + Fe{CN)5L " J- - (Co(riH3)gdmso "^[Fe(CN )5L 1 Mit expecte

2 Fe(CN)g " + Co(II) + + dmso ODS .1

The empiric the electron transfer process is preceded by formation of a precursor ^ = l outer-sphere complex between tiie reactants. obs ;r~ Numerical analysis of the observed saturation behavior in This rate 1, mediate is the measured rate constants, indicated strong association CODIrphen' (K = 400-550 M" ) which independed on the nature of the ligand L. The limiting rates of electron transfer reactions, in the range of 3.0x10 - 7x10 s , followed closely the redox potentials for the several pentacyanoferrates (0.3-0.6 V) with a linear relation- CODlrph< Ship as predicted from Marcus theory. ihis postul; observing c! The enthalpies of activation for the reactions arise rate law 3. observed us: exclusively from the intramolecular electron transfer process (22-26 Kcal.mol ). The ion pair formation contribute in approximately a same extent as the electron transfer process, (15-20 cal.rol" deg ) to the observed activation entropies. lho Nacion Academy of Sao Paulo.

V* iS 104 11.23

: SUBSTITUTION REACTIONS OF FIVE-COORDINATE IRIDIUM

National Chemical Research Laboratory, C.'s.l.R., P.O. Box 395, Pretoria 0001, South Africa.

I'tii- reaction of the five-coordinate CODlrphenX complexes CODlrphenX + on Me0H, C0DIren+ +X" +'"phen 'U COD = cvclo-octa-l,5-diene phen = 1,10-phenantrolene en = othylenediamine X = I, SCN ha been studied kine'tically in order to ascertain whether the substitution reactions i'f t huse ooordinativeiy saturated s~eoies would proceed via a dissociative mechanism,

CODTrphenX ^JL> CODlrphen* +X~ en Ik, (2 i C0DIren+ + phen i'iit expected rate law for this reaction scheme is kj [en] kobs " .1 + K[X" ] ' (3) The empirical rafe law found for reaction 1 was however

k = CX [en] N bs (4) ° Co + C3[en] + CL [X-]

!"his rate law can be explained if the buildup of a stable five-coordinate inter- mediate is introduced into reaction scheme 2; CODlrphen"1" + X" ^^ CODlrphenX

en=N^N K, N ,., 1 " J)

CODlrphen CODlr(N + phen .his postulate wa& tested by using sterically crowded ethylenediamines and observing the conditions under which the reaction could be manipulated to give the rate law 3. The presence of a "stable five-coordinate incermediate"was also observed using Lhe four-coordinate CODlrphen"1" C10^~ complex as substrate.

: I —I* lj| Acknowledgment: The authors acknowledge financial support from the Conse- lho Nacional de Pesquisas, the National Science Foundation, the National Academy of Sciences, and the Fundaçâo de Amparo à Pesquisa do Estado de Sao Paulo.

i: .24 105 /KINETICS r T.;E :;st: re.-.. o; LLCANT EXCHANGE REACTIONS i >: A CERTAIN COBALT(III) RH0DIUM( AND TIN(IV) COMPLEXES IN TRlALKVLPhOSPHATES. B. Chakr< R.C. Pau', O.~>. Sliartna and .1 ..C^J^ajJLa, / ^ Kalyanl Department >: CV-r.-slry, Pol,jab University, ' Chand igar||-i bOG IJ, ; :n:i i a . Mechanis

T'K' exchange of warer i-,i dimi-ciiyls'.'lphoxide UMSO) with criethyl- between ;..hos..'lia tf (TEP) in (a q'ju > u.-n ! a H n> i ne c o o a I f ( 111 ) per chlorate and overall (d <.mv .. hy 1 si.11 piii- y i de ) ppn - .sa ::. . -i • c > a ] t ( 111 ) p »' r c h I o : • i '• respectively in

T'E -' is • • :i i ::K> ! •.; •- u 1 a r react HI >• The pro.juor of the .• -.change reaction, Rh(BigH)

!t-. -i t h ;• i , h o b p h a t e ) p e n t a a n> i n • * ob lt(ITI) pt-rchlora : e , nab been charac-

r Le" : sea. > rid in e (Py) and 'f] ori'.e ion (.ibrained • rom acetylchloride) The rate H., o/nMSO rhei p é n t u a tn i n e c :.• .-> a i c (III) -onplexes. Th e rate method. '. •->••• 'or r 'e tut ire range i .-• . '..;• • = k + k _ [complex _,;C' T y j . Besides the The valu vm ip... ", cxciiange reaction, '• herf exists j reduction process involving ;OPV- rsion of some occahedr.. •obalt(III) to tetrahedral cobalt(III) species. Tht- 'Mlues of JiH** a"H 'iS*. which have be^n calculated from the rate data at different tempera turea, support rhat the activated complex k ca has Che properties of S.,1 pr>M- e.v..

Whereas r.l.r complexes b i s ( 2-met hylpyr id int; ) te t racb lorot in (IV) and The stre bis(quino1inejretrachlorotini 'V* ionise instantaneously to give I" > Br" (2-CH^C H N) Sni'L and (C H.N) SnCl* and chloriuu ions in TEP, trime- "bigaanid thylphospha te (.T>;P) and t r i-n-bu t y] phospha t e (TBP ) , the complexes bis seconà s (pyridine)tetrschlorotin(IV),bis(3-methylpyridine)tetrachlorotin(IV), give str bis(4-methylpyrid me)terrachlorotin(IV) and bis(isoquinoline)tetra- first st chlorotin(IV) are solvolysed in TEP.TMP and TBP. The solvolytic transit! reaction and substitution of amine molecules by chloride ions in TEP, metal a* TMP and TBP follow a dissociation mechanism. The variations in the that the rates of these reactions ha\e been int erprotcd in terms of sterir and stripped electropositive inductive effects of the substituents on the pyridine leaving nucleus. decrease experime] 106 11.25

/KINETICS AND MECHANISMS OP AQUArlTO2I OP SOME DIACI3X)BISBIGWJANII>E- RHODIUM(III) COMPLEXES B. Chakravarty, Department of Chemistry, University of Kalyani, Kalyani 741235, India

Mechanistic studies on the aquation of Rh(BigH)2xt, where BigH = •biguanide1 and X = Cl~, Br~ or I", were carried out eonductdmetrieally between 32° and 50°. Release of X takes place in stages and the overall reaction may be given as J

2+ x Rh(3iSK) Rh(BigH)p(H 0)X —iS22i-= __ First step * * Second step

The rates of release of each halide ion were derived by a graphical method. Activation parameters were obtained from 3yring equation. The values are as follows I

Ml - x Cl" Br r Cl" Br I" k cals mole 14 15 .1 17 .4 12. 3 13 .9 15 .3 e. u. -25 -21 .8 -14 .8 -34. 4 -32 .6 -27

The strength of Rh-X bond, as indicated by AE values, varies as I" > Br" > Cl" showing class 'bf character of rhodium(III) in biguanide complexes. The plots.of AS values for the first and second steps of aquation vs A S >.vdr tion °^ TesT>ec^v'e halide ions, give straight lines of slope 1.0 and 0.9. This indicates that in the first step of aquation, Rh-X bond rupture is virtually complete in the transition state but in the second step X is.weakly bound with the metal atom along with the incoming H-0. AS values also indicate that the loss of second halide ion takes place along with a proton, stripped off from the 'aquo' ligand introduced in the first step, leaving it as a 'hydroxo' ligand. Release of H is supported by a decrease in the pH of the experimental solution and also by other experimental evidences. U.K. 4 L07 !• S-

Ki::E7I'"S Or J.-L OXIDATION OF TRIS (2-PYRIDYL-a-METHYL (METHYLIMINE) ) IRON(II) BY (IV)

Dora Soria, Mar.na Lessa de Castro, and Helena Li Chum Institute de iuimica, Universidade de Sao Paulo, Sao Paulo, Brazil

The oxidation of tris(2-pyridyl-ocmethyl(methylimine))iron(II),

Fe H5N-C(CH .)=NCH,)., Fe(PMM) by cerium(IV) is another example of Ligand-oxidation reaction proceeding via the ferric complex involving iron diimine complexes. Trie behavior of tnis complex with a mixed aliphatic- aromatic diimme ligcind is analogous to that exhibited by aliphatic 2 diimir.e corr-.ie.-:cs , e ..;•,, '...-i?. 'glyoxalbis (methylimine)) iron (II) , Fe (GMI)2 +"L" (K.L. Chum and . . Krunholz, Inorg. Chem.., 1_3, 514, 519(1974)). These two types cf iron sumine ccinpiaxes differ from the well-known aromatic diimine complexes in which the oxidation by cerium(IV) yields the corresponding "erric ccr.pounds, independent of acid concentration.

+ The oxidation of Fe(PMM)3 by cerium(IV) is reversible and 3T stoichiometric yielding FeiPMM:3 and Ce(III) at [H2SO4J>4.0 M. At lower acid concentration, e.g., [H^SO-]=1.0 M, the consumption of Ce(IV) + increases tc 10-11 equivalents per mole of Fe(PMM)3 depending on the rate of addition of Ce(IV). The primary step in the oxidation at low 2+ 3+ acid concentrarior, is; Fe(PMM),*' + Ce(IV) r^= i Fe(PMM),"' + Ce(III), with K = \ 1. ^± G.1)xIO^', where E (complex couple)=0.71 V vs. see and Eo< i'Ce UV) /Ce il-T) ) = 1.12 V vs. see. The rate of decay of the ferric form regenerating the ferrous complex and yielding new ligand-oxidized products is a second-order process in the ferric complex. The overall rate constant is 2.0 ± 0.2)xlO4M~1s~1. A mechanism for this reaction 2+ analogous to that proposed for the oxidation of Fe(GMI)3 is compatible with the experimental results. The stoichiometry of the reaction, major oxidation products, and detailed kinetic studies will be presented.

Kl K2a Acknowledgment: The authors acknowledge financial support from the a . Fundacao de Araparo a Pesguisa do Estado de Sao Paulo. d-

. •:. ' > ; •* 108 III.a.10

"RAMAN SPECTRA OF SOME COMPLEXES OF ANTIMONY PENTACHLORIDE Y. Gushikern , 0. L. Alves and V. Hase Instituto de Qufmica, Universidade Estaduai de Campinas, CP 1)70, S.P., BrasM

Antimony pentachloride has been used to define the donor strenght of various Depar Lewis bases from thermodynamic data. An attempt to correlate the metal-iigand or metal- Maryl -chloride stretching vibration with donor strenght has also been used (M. Burgard, J. Brunette and M.J.F. Leroy, Inorg. Chem., 15, 1225 (1976)). However, this correlation by Rama;: using only the position of the frequencies does not appear to be quite simple, since viz. , even for \)MC1 they are reasonably coupled as can be shown by potential energy distri- bution (PED). f (C6ri For a series of complexes SbCl5.L

a 0nly for SbCls0 moiety

TABLE 2. Urey-Bradley force constants of SbCls.L (mdyn/8)

L I II III IV V VI VII

K(MX)eq 1.682 1.582 1.562 1.580 1.616 1.616 1.597 K(MX)ax 1.884 1.859 1.689 1.700 1.787 1.728 1.742 K(SbO) 0.364 1.300 1.471 1.570 1.853 2.131 1.530 K1a 0.134 0.171 0.156 0.131 0.160 0.100 0.131 K2a 0.329 0.329 0.361 0.333 0.373 0.501 0.387

a stretch-strech interaction force constants; K. « (MC1-MC1) trans and K2«(MC1-M0)trans. III.a.11 109

-•••"- '•> :.''.r'.:J.nS OF PHOSPHIJE SULFIDE AJD PHOSPHINE SELENIDE .IGAIiDS / R. K. Khanna, W. D. Warner, and J. D. Mitchell Departr^rt -^ Chemistry, University of Maryland, College Park, Maryland, 20742, U.S.A. Raman dpecira if several scries of new pnosphine sulfide compounds,

viz. , (Cl.:;..) ,P ,S)Ch2PRR', (Cgiij) ^P (S)CH2P(S)RR' , (C6H5) PCH2P(S)RR',

+ 1 [ (L'6ii5)? P io)CH2PRR2] or", and [(Cgiu) P (S) Cl^PRR ]M (COJ 4 , wnere M

1 is Cr, rlo, or n and R -- R' = Cli, or i-CAi-, and R = CgH5, R = CH., or i - C.,'. ~, ..aVi3 bo.n :.'taine: \nd the pnospnorus sulfur str^tc.ing frequencies .danti^ied. Tne variation of -D_. in tne compounds and the cnanges or -^_^ upor. coordination are discussed and compared u.o . .,_ i:'. ;o±ia:' :: .!-/:= ..line ox-de complexes. and dj.it-.on, tertiary phosp.-ir.e selenide [e.g., (C,H,-) PSe, —- 0^3

(Ct.H.) (:-.-C4i:9)PSe, (CgH5) (n-C4Hg) PSe, (n-C4H9; PSe and others) complexes of various metal systems have been prepared and phospnorus-31 nmr spectra racorded. Phosphorus-31--77 coupling is observed and trends in Jp q are discussed for these compounds. 110 y III.a.12 M J OF i(- '-'7i) SPECIES IK LOW TEMPERATURE MATRICES. Malika ';irabelsi and Andrée J.outellier Ecole "ationale Supérieure de ."'••imie de Paris (Prance). +Ecole "ormale "ultérieure, iv> rue de la Mberté- Le Bardo (Tunisie). '"^Laboratoire de Spectroohimie Moléculaire ParisVT,Bat F, £ rue "uvier -7^005 Paris (France).

*"i(PT-:.. ) species ( n =!,?.,",>were identified in mire PH., and PH, - dilute matrices(K.Trahelsi ard A.Loutellier, J.Mol.Struct. in Dress). These species were or•ni^ec by cocondensation of mono- atomic nickel vapor wit:-, caseous PH.. or. a Csl tare-et cooled at TC ¥.. '"he nroducts of cocondensaticr. :ave beer, investigated by matrix infrared sr>ectroscoT>y, mainlv in the F-P-F bending ( --T) and Mi-P stretchingv5C-2: 0cm" ) res-ions. -Evidence for their for- r p mation was made on the lasis of known assignments or. F(" Or,( F,) complexes where the siinmetric P-P-W vibration in the coordinated lip-and lie at about 2C-?Ocm~ higher than the free ].ifrand (M.Pir-or- cne,A.Loutellier and M.Pankowski,J.Orcanometal.Chem.2_2,2CI(I°70) ). Two types of results were obtained depending on experimental con- ditions : T) In üure PH, matrix, only one complex was obtained. After eli- mination of excess of PH.,, this compound was identified to the complex "ri(PH, ), which ha? been Drepared Tjreviously(N.Trabelsi, Q A.Loutellier and M.Pi^orp-ne, J.0r^anometal,Chem.:î_0rC45(I 72 ) and A.Loutellier,M.Trabelsi and M.Biforsrne, J.Org-anometal.Chem. in press) II) Tn PH,-Are-on matrices , the four intermediate suecies Wi(pH_) j 7 n m (n =If2,3,4) were identified . heir identification was made on the basis of the TTi-P stretching freouencies of the individual compounds and the variation of relative band intensities. III.a.13 111

*. NORMAL COORDINATE ANALYSIS,BY ITERATIVE CONSISTENCY METHOD,FOR +2 64 68 •."TV vv, [zn(NH3)4l WITH Zn/ Zn and H/D ISOTOPIC SUBSTITUTION. t / Juan Roberto Anacona.

Departamento de Quimica, Universidad de Oriente, Cumana - VENEZUELA.

A large number of seiuiempirical methods hjtve been proposed to solve the inverse vibrational problem. However, this number ia sharplv re- duced given the necessary condition that the force constants correctly interpret the vibrational spectrum of the isotopic analogues, a consequence of the Born-Oppenheimer approximation.

In the present work, force constants calculation were carried out by the iterative consistency method and the band assignments have been confirmed by the calculation of the potencial energy distribution for each normal vibrational mode for the l?4Zn (NH,) . J2, \_68Zn(nK~) T and

Zn(ND3)4J ions.

The symmetry force constants give good estimation of the Raman and IR observed active vibrational frequencies and a comparative study of these constants with the Urey-Bradley force constants(K.Sakamoto,J. Takemoto,T.L.Chow,Applied Spectroscopy 25,352(1971)) and with the pseudo-exact force constants by using point mass model (A.Muller,K.H. Schmidt,G.Vandrish,Spectrochimica Acta 30A,651(1974)) have been carried out. The molecular geometry, the symmetry internal coordinates and the fundamental frequencies used for the calculations are the same in all models. Fifteen steps of the iterative procedure were run for 64 +2 68 + 2 68 + 2 each ion pair ( [ Zn(NH3)4 J and f Zn (NH^ ] , \}*~' Zn (HH3> 43 NA 2 and [ *n(ND3)4r ). Finally,it should be pointed out that with the present method of cal- culating force constants,as well as with any other semiempirieal method of least-square determination the inverse vibrational problems remain indetermined,inasmuch as the final matrix F depends on the zero approxim-

ation FQ.However , the iterative procedure has the advantage that rather high variations in the zero approximation matrix F introduce too small o or no changes in the final matrix F.This permits self-consistent sets of force constants to be obtained in series of molecules as indicated above re-orientation of the bonding of the RSeO2 groups.

112 III.a.14

$"! THE NATURE OF BOND IN THE CONDENSED OXY-HALO ANIONS ~/ G. Mitra Department of Chemistry King's College 133 North River Street, Wilkes-Barre, Penna. 18711 U. S. A. During the past decade quite a good number of salts of the condensed ions of fluoro and oxyfluoro monomeric ions have been reported. 2 K TeFs + 2KOH • K 7e.,FR0 + 2KF + \\2Z 2 >V\/0F.. + 2KOH * K V,F 0. + 2KF + H,0

These new ions are related to the parent monomeric fluoro or oxyfluor ions in 2 the same way as pyrosulphdte ion S-0^" is related to the sulphate S04 " ion. In addition to Te and V other elements such as Al, Re, Ta, W etc. can act as the central elements in these condensed ions. The M-O-M links have been studied in solutions as well as in the solid state. IR and Raman spectra of these compounds suggest that the bond orders of the M-0 links are appreciably more than one. The vibrationai peak of the M-F links do not change to any great extent from the one shown by the monomeric parent ion. Due to change of symmetry, however, the intensities vary in a few cases. The solid state Raman spectra of a few compounds are given below.

Table 3 1 Compounds Raman peaks in cm' 935, 900, 640, 490, 360, 325, 240, 210

KJa2F120 635, 600, 465, 270

K6W2Fg05 952, 915, 817, 370, 305, 255 We0 688, 486, 441, 420, 295 The structures of the potassium salts of a few of these oxyhalo anions have been determined. They are mostly tetragonal. mechanism very unlikely.

III.a.15 113 •Jf (II) HALIDE COMPLEXES OF TRIS(DIALKYLAMINO)-PHOSPHINE SULPHIDES

Chiu Sung-Lit and D.S. Payne A. Department of Chemistry, University of Hong Kong, Hong Kong.

Examples of mercury(II) halide complexes with various ligands covering the-ligand to metal halide ratios of 2:1, 1:1, 2:3, 1:2 are known, and their structures are based on the tetrahedral stereochemistry of four coordinated mercury in oxidation state II. The only complexes which it has been possible to isolate all have a 1:1 ratio of ligand to mercury(II) halide. Both simple and mixed halides of mercury(II) have been investigated. The infrared and Raman spectra of these compounds are reported and the trends in these spectra correlated with proposed structures. i.\0 o

114 III.a.R.2

DES MOLECULAR STRUCTURE FOR THE NEW COMPLEX SALTS FORMED BY THE (PtClfi)2~, — -, (.AUCI4T" ANIONS WITH THIAZOLE DERIVATIVES, A. Doadrio *, D. Craciunescu *, C. Gh'irvu**, J. Baztan*. *Department of Inorganic Chemistry, Faculty of Pharmacy, Madrid-3, Spain. **Chair of Physical Chemistry, Faculty of Chemistry & Chemical Engineering "Institutul Politehnic Iasi", lassy, Romania.

This paper describes an investigation of complex salts of (PtCl^) try g", (PdCl^)2", (AuCl^)" anions with the following ligands: 2 Aminober zothia2ole; 2 Amino-6 bromo !-«nzothiazole; 2 Amino-4 Chlormethylathiazo].e; •- 2 Acetamido-thiazole; 6-Amino-2 mercoptobenzothiazole; 2-Amino-4 MethyA-i-.ui?.- zole;- 2 Aminonaphtdl {1,2} th.iazole. I.R. spectra of the complex salts (PtCl6)(LH)2, OsCl6)(LH>2, (LH)2/ and (AUCI4) (LH)~, where L=the abo^e mentioned thiazc>les - we-e r ded between 4.000-250 cnrJ in KBr pellets ar.d hex.achlorobutadxene nulls. Pro tonation of the -NH2 group was assigned on the basis of thP presence o,:' the 1 J-NH3+ bands (2.800-2.900 era" ). Such thiazoles formed I.H.'-3. (Inters •l»c-~ lar Hydrogen Bonding) always through -NH2 gr the thiazoles. The presence of the entire entities (OsClft)2-, (PtClg)2", •— (PdClg)2", (AuCl4)~ was confirmed by the examination of the far I.R. region, where bands appeared at 330-315 cm"i ranges. Results of the antitumour screening (on animals bearing establishe'-1, L1210 and P388 tumours) were also discussed in connection with the 'structure of the new complex salts. IIi.a.R.3 115

" New approximation in the iterative consistency method » Force constants oalcu_ AND COPPE lation in Hi(CN)"2 , Pd(CN)"2 , Pt(C!J)~2 and isotopes derivatives " Kamdouh S ( Departmen > Juan Hoberto Anaoona Alexandri C- Departamento de ^u£mioa,Universidad de Orients,Cuman4,Venezuela. "etai-:igand vibrations of coordination compounds are the most important because The coord the carry direct information on the compound structure and on the nature of the me_ (CPANA, H tal-ligand bond. Metal-ligmnd vibrations suffer an isotopic shift if an atom of and l-(2- either the metal or the li»and is isotopically 3ubstitut«d. Thi3 technique is very copper sa useful in assigning the vibrational frequencies of III and Raman speotra. CoL2-2H20 The hi-jh sensitivity of the Iwnatrix of normal vi'irationa] nodes to the variations (in alcoh : PAN gave of the molecular force field has recently been demonstrated ( VvrocalJ,R.AnaconalR> ClavijOjJ.Mol.Structure 27,49(1975)) usinc the iterative consistency method. neutral f iDnizatio: In the present work,using the above mentioned method together with a new approxi_ ated in t mation,the force constants matrix for the I-I(CMj~"~,(M » tfi,PdrPt) ions in their natu_ acetone, ral iaotopic abundance its calculated from the experimental vibrational frequencies the solve (a.3.Kubas,Ii,H.Jones,Inorg.Chemistry 13,2816(1974)) and ieotopio shifts of bands are complexes theoretically predicted when ^C or ^!T are substituted into the compounds. a half of In order to solve the equation " ? L «• Li\,the iterative method normally assu_ transitio mes the equality of the force fields in two isotopically different molecules (F, = i" ] 2 Teller di and calculations are started with an approximate matrix 7 .In the present work an xes are o additional approximation is considered : if the factor &m/m 4&I (Am - mass diffe_ green in rence of the two isotopes, m - atomic mass of the element),it may be assumed that The Ni II experimental frequencies must be equal (A. j «-A- ) and the iteration is started con_ 2 peaked n» sidering a G-matrix for the normal molecule and another G-matrix for the molecule argued to with any isotope of M , vibronic The final F-matrix is obtained when the difference between ?y and f is minimum nujol mul (A ? < O.OI>),a condition which is normally fulfilled after ten iterations. The media. T resulting tore* ooaataat* aairix yields good pr»diotion» of experimental frequencies (IR and Raman speotroscopy) of M( CN)7 and M(c"lO" ions after modifying the Gr-matrix . Present The influence of the faotor L m/m on the determination of the molecular force field is also analysed . I 116 III.b.8

£ COORDINATION CHEMISTRY OF SOME AZO COMPOUNDS WITH COBALT, NICKEL AND COPPER SALTS., Mamdouh S. Masoud , T.M. Salem and M. Elhenawi Department of Chemistry, Faculty of Science, * COPFEH •. I Alexandria. Egypt. STABLE C:

The coordination chemistry of o-carboxyphenyl azo-B-naphthylamine M. Pasqual (CPANA, HL); 2,4-dihydroxy-phenyl azo-2-hydroxybenzene (DPAHB,H,L) Istitutc and l-(2-pyridylazo)-2-naphthol (PAN,HL) with cobalt, nickel and copper salts was investigated. CPANA formed CuL, NiL Cl-HgO and It is ver monoxide CoL2-2H20; DPAHB gave Cu (H2L)Cl.H20 ( in alcohol), Cu(HL) H20 nevertheI (in alcoholic ammonia), Ni(H2L)2; JH20 and Co(H2L)2. 4H20 while of stab.e PAN gave Cu(L)Cl, Ni(L)Cl.H20 and Co(L) Cl.SH^of CPANA exists in neutral form in solvents with low dielectric constant slight B.G.DeBoe ionization takes place through hydrogen bond. DPAHB was predomin- 14, 2051 ated in the azo form in alcohol and in the hydrazone skeleton in copper (I.) • acetone. The structure of PAN is independant of the polarity of very stab! the solvent. Copper-CPANA possess the £" bond and the other copper for under* complexes have the copper II band leading to a transition within choosed as a half of a dimeric molecule, probably due to d —^ d 2 2 bases. DJ transition. These complexes are subjected to a considerable Jahn- [cu(dien) Teller distortion with square planar geometry. The cobalt comple- an example xes are of octahedral geometry. The violet PAN complex becomes X-ray stri green in chloroform or acetone, may be due to oxidation of Co II. of the dor The Ni II-PAN exists in a square planar geometry. The doublet (II), (L=I peak«d nature of the ocbahedral bis Ni II-DPAHB complex ean be like (I) e argued to the closeness of the Eg state coming from 1D with will be i: vibronic coupling. The square planar nickel- CPANA complex in molecular nujol mull and at low pH's becomes of octahedral geometry in basic carbon mor media. The electronic transitions were determined. discussed carbonyl c dinuclear Present address: King Abdul Aziz University, Faculty of Science, carrier pr Chemistry Department, P.O.Box. 1540 Jeddah, Saudi Arabia. \ ; III.b.9 117 > • \ •

Vj / y > / THE iV-UTI • V V/^PROFERT: •* c OPFEH ;.: -AMINE CARBONYL CHEMISTRY: SYNTHESIS AND STRUCTURE OF It, C. Oazo STABLE C-PFER (I)-CARBONYL AND -OLEFIN COMPLEXES. '•a Lepartnw M.Pasquali, ".Marchecti and C.Floriani 860 37 1 Istitutc di Chimica Generale, Universita di Pisa, Italy. The dis< Izv.i In: It is very *-e 1 1 kn^vvn that copper d) -amine systems absorb carbon the beg: monoxide M.I.Bruce, J .Crganometallic Chen.., 4_4_, 209, (1972)] , the com] nevertheless -here is r.c report on the synthesis and reactivity of I•iIL ( of stab.c ::'pper(I)-ainine carbonyl complexes |M. R.Churchill, The con" B.G.DeBoer, F.J.Rotella, O.M.AbuSalah and M.I.Bruce, Inorg.Chem., complex* 14, 2Orl (197') and refs therein"]. Our investigations on the The stu< copper 111 -amme systems gave both the possibility to isolate the exii very stable copper(I)-carbonyl complexes and to find an outline ir.teratc for understanding the factors affecting the Cu-CO stability. We choosed as ligands polydentate aliphatic amines or Schiff's bases. Diethylenetnaminecarbonylcopper (I) tetraphenylborate, and may [cu(dien) (CO) JBPh4, tl), ( ^c=2O8O cm""), which can considered complex* an example, was isolated as thermally very stable compound. The isomers X-ray structure analysis shows a pseudo-tetrahedral arrangement express1 of the donor atoms set N,C around copper(I), [cu(dien)LjBPh., the trai (II), (L=RNC, PR,, olefins) were similarly obtained. Complexes The stu< like (I) and (II) , for which the chemical and structural features MIL in • will be illustrated, can be considered models for metal-induced may lea< molecular activation processes. The reactivity of coordinated formed, and olefins towards nucleophilic agejits will be to eluc: discussed in detail. The successful isolation of very stable complex* carbonyl complexes of copper(I) leads to the synthesis of some Lecture: dinuclear copper complexes miming the hemocyanins carbon monoxide 19"4, p. carrier properties. Also soi Cu(II) t of MIL < The kno\ stiiiula- 118 III.b.10

/ THE .MUTUAL INFLUENCE OF LIGANDS (MIL) ANT THE STRUCTURE "FRGFERITES OF Cu(II) COMPLEXES <.•. Jazo Lepartment of Inorganic Cheiristry, Slovak lechr.ioal University 860 37 Bratislava, Czechoslovakia Institut The discovery of the trans-effect fifty years ago (I.I. Teherna.^, Izv. Inst. po izuch. platiny A, 213 (1925); 5,, 115 (1927)) means u.s.s.a. the beginning of an aimed research of the consequences of MIL on The it the complex properties. It has been found that the cont>equencies NiL2X2 (I of MIL depend on the electron properties of the central atoms. Iva,K,Csa^ Ihe contribution will deal with the question of the MIL in Cu(TI) acetone ,ci complexes. The study of some groups of Cu(Il) complexes in solid ?tate showod as a resu the existence of a mutual relationship between changes cf the The ©a ir.teratoinic distances central a tor. - ligands in coordination tiae cori^o -olyhedra. This dependence is due to an expressive plasticity of It is Cu(II) polyhedra U'. uazo e; al., Joord. Chen.. Rev. 19, 253 (1976)' nate : ;- and may be understood as a special manifestation of MIL in Cu(II) central complexes. It is interesting that in the izomerisation of distortion I0~4torr isomers (J. Gazo, Pure and Appl. Chein. 3_B, 279 (1974)) the most Electr expressive cnanges in interatomic distances mostly occur on one of to distor the trans-coordinates. the value The study of various systems with Cu(Tl) complexes showed that, ths and 3,Ifa illL in the complexes with different bonding properties of ligands Polyhe nay lead to innercomplex redox changes, in which radicals are as In sal formed, and Cu(II) becomes reduced to Cud). This fact allow? e.g. ionic cha to elucidate tne halogen&tion reactions of halogenocopper(II) cation of complexes ^J. Gazo, Kovel in Coordination Chemistry, Section The sii Lectures of the 13th ICCC, Poland 1970, Pah'st. wydaw. nauk. , Warszawa tht elect

19"4, p. 293.) and JSw±2p Also some thermal decompositions and indirect structure research of Howeve Cu(II) complexes (e.g. by means cf IR spectra) indicate the effect than iodi of MIL on the complex properties. The knowledge of the concecuences of MIL in complexes of Cu(II) stimulate the new exploatations of compounds of this central atom. THE 0 -Il.b.ll i 119 / SZWffiHESIii *MD STRUCTURE OF CLOSODUDECABORATE MICKEL(II). Cencro C I.A.aakharova,IwT,Kuanetsov1Yu.L.Gaft no - Vii Institute of General and Inorganic Chemistry Academy of Science U.S.S.H.. Moscow, U.S.S.K. The sr.uc

The interac. ion of nickel(ll) oooplexes of the general formula solutiof

IV5 B X NiI»2X2 (X-Ph-jP, A*Cl,Br,I,CNS) with closododecaborate 2 T2 I2 suits, p JvafKjCSjX-H, .;i ,Br) is studied by the method of isomolax series in ti., Ga22 acetone.methyl .yaniae and mixtures of soxvents at 20°C. by a sue Wi£ Cl # GCZ-jC;, (I) ana '.'iB^Sr^. 7CK-.CW (II) complexes are found I2 I2 (1953)]. as a result ci' abort mentioned reactions in dry methyl cyanide. We have The jnagnetiCjSpectz'oscopic ,11-ray photoelectron characteristics of the confounds are studied. differen It is founded that ail of the methyl ^yanide molecules are coordi- thetical nate :; nitroger. at on. tc :o;::piete thb coordination sphere of the By actioi central atora and are not lost while heating up to 350°and in vacuu::. decomposi IO~4toxr. reaction Electronic spectra of I and II show the presence of transitions due structure to distorted octahedral environment oi' nickel that quiet agree with the values jf effective magnetic moments equal to 3,29 B.M. for I la, whicl and 3,ib B.M. for ".'I. inally p: _2 Polyhedral anions ^i^iz itave tiie same 3Pectrosc°Plc characteristicfc as in salts of aloali and alcali earth metals which whitnesses to the ionic character of interaction between borane anion and a complex cation of nickel. The sifetitut-i-on of clorine by bromine m an anion does not change Z the. electronic state of nickel, as i^Sp - 857,7*0,2eV for I la and ^-j^P * -5'",6+0,2eV for II. However the borane anions didplace the electronic density stronger resul than iodide-ion ,lr- the initial complex Lol'JiIp(E,,.2p ' »854,8+0,2eV). The cours (II) are 120 III.b.12 ^/ON THE OXIDATION COMPOUND OF BISBENZAMIDOOXIMATONICKElA II) >/ k° MaLatesta, Go La Monica e Mo Manassero Centro CNR presso l'Istituto di Chimlca Generale dell'Universita di Mila no - Via Venezian 21 - Milano (Italy).

The study of the nickel compound (I), obtained on oxidation of a basic solutioft of nickel(II) salts and benzamidoxime was reconsidered. The re suits, published by one of us about 35 years ago [LoMalatesta, R.Pizzot- ti., Gazz» Chim. It. Jl» 564 (1942)], had been infact partially contested by a successive work [D. Bandyopadhayay, Journ. Indian Chem. ^0, 119 (1953)]. We have now proved that (I) is formed by a Ni atom, chelated to two different ligands: the benzamidoximato anion, and the anior of the hypo- thetical -Cfl-, * (II) species, not stable in the free state. By action of acids on (I), compound (II) is set free and it immediately decomposes giving quantitatively dinitrogen and benzonitrile. The same reaction, in presence of iodide, gives two equivalents of iodine. The structure of (I) was confirmed by diffractometric X rays analysis as la, which is only slightly different from one of the two structures orig-

inally proposed for it (Ib)u HO 0 0 N—-Q tN=N C-(p

la H H H H H Ib

The results of Bandyopadhayay on the contrary are completely to reject, The course of the reaction giving (II) and the oxidation reaction of (II) are temptatively explainedo Fundaçao de Araparo a Pesquisa ao tswao ae

III.b.13 L21

NOVEL FOUR AND Fi\ECOORDINATE Ni(II) COMPLEXES WITH A MONODENTATE GROLT V LIGAND:

V.Partiguenave, M.Dartiguenave and C.r>'Hem 'I U.R. .'.dburatuire de Chimie de Coordination au CNRS SP -i|-Jj .Toulouse , France

iae nronerties of bi, cri and te traden ta te arsine(III) ligands in stabilizing S complexes with high oxydation state is now well known. On the other hand, "wnoJentate tertiary arsint (I1T) is reported to stabilize metals in low .m state, very few compounds have been isolated with nickel (II) ( C.A.Mc .%u 1 : in Transition metal complexes of phosphorus, arsenic and antimony ligands- Me M ip. rid. >9~3) . The ana.ogy of tertiary arsine and phosphine, and the capabili- ty •"":" phosphine in stabilizing transition metal complexes in various oxydation states coordination ... prompted us :o investigate the reaction of As(CH_). on Ni salts. 3r', We report here the synthesis and characterization of the tetracoordinate XiM,(As>Ie j„ and pentacoord ina te NiX,, i AsMe.) . complexes ( X = Cl,Br,I,CN,NCS,AsMe,'. "ihese complexes represent the first well characterized complexes with Ni(II)-AsR„ jonas. They are prepared in good yield by the reaction of AsMe. on the nickel salts, ; :-. uichloromethane or ethanol, under nitrogen. Analytical results,molecular weights, conductivitv data indicate that they are monomeric and non electrolyte, except vNi'AsM*,•- which is a 2/; electrolyte. Effective magnetic moments, determined in tac- soîiù state, are in the range 0.1 to 0.9 BM expected for d low spin complexe- Ail the compounds are intensely colored.

Their variable temperature electronic spectra ( 77 to 295 K), in the solid stat'- and m solution with excess ligand, and dipole moment determinations allow us t< propose :

- for the tetracoordinate NiX9(AsMe.)0 complexes,a trans-square planar structur*- K at

- for the pentacoordinate NiX9(AsMe.) and[Ni(AsMe )X complexes, a trigonal .upvrarr.idal geometry with the trans-BPT configuration for X =CN,NCS,AsMe. (a) and cne cis-eq configuration for X = halide(b).

AsMe.

AsMe, AsMe AsMe sMe 3

In dichioromethane solutions, the complexes are dissociated. Temperature depen- dant equilibria are observed between the square planar and trigonal bipyramidal complexes. All these results will be discussed by comparison with our previous results on analogeous PMe, and SbMe. Nickel(II) complexes 122 III.b.14

1 V J CG...T0U1D3 OP 2-Iv^JiuC;Arl O3JiCII.iIDAiiGLJ • 0' / V and I). Padmanabhan Department of Chemistry, Indian Institute of 'j}echnolo;jy, Liadras.600 036, India.

A number of coordination coinpounds oi geiieral formulae, :.(cibm) and where M = Co11, ili11, , Od11, , Ou1, and Au , labiaH = 2-raercaptobenziinidaaole, n = 1 or 2, X = 01 , * i i Br , I and 1TCS ; m = 1 or 2, has "been prepared. She compounds are characterized by conduct?:^e, ur^netic, electronic ani i^-Tivx1?." spectral measurements and themcl bshoviour. I he u£.p;etiu antl visible spectral data suggest the* Jo(II) conplexes are tetra- Uedral whereas Hi(II) conplexes. are square planar. J'roia the infrared spectra it is co.icludeJ what in LKwbm) type complexes, tlie ligsiid is bonded to the ..ietal tnroujh the IT and S atoius, in

r(mbrarl)p:^ throush the 3 at on or.ly and in I,I(mbmh)Xp the tv;o imino Y. ato;p.s of the ligand pre bridgir; the adjacent metal atoms. t/& III. b. 15 123

0, CHROMIUM(ill) COMPLEXES WITH ISOXAZOLAMINE DERIVATIVES. 7 M. Biddau, M. Massacesi, R. Pinna and G. Ponticelli Istituto Chimico Policattedra, Universita di Cagliari, Departs. Via Ospedale, 72 - 09100 Cagliari (Italy) 277028,

Complexes ot chromium(lll) with 3-amino, 5-methylisoxazole(3-AMI) and 5- I -amino-3, 4-dimethyl.t$oxazole ( 5-ADl) of general formula Cr(L)nX3'mH2O structu (where X = Cl, Br, I, NO3; n = 1-4; m = 1-8) have been prepared and cha- based o racterized by magnetic and spectroscopic techniques. The ligand field pa- rameters have been calculated and compared with similar complexes contain- Iat.J.Q ing OO.1X3 and ON3X- chromophores. account The complexes of 3-AMI and 5-ADI have been prepared by reaction of the the MO corresponding metal salts Ln refluxing chloroform and methanolic solution origin) of the ligands. All the compounds were purified by means oT >tep««*_ted washing with hot chloroform or acetone. empiric On the basis of the magnetic moments and the electronic spectra we can. type, w. propose an essentially octahedral geometry, the \, values in the range 3.4- heavy a -4.3 B.M. are as expected for three spin-only term (B.N. Figgis and J. Lewis, Prog. Inorg. Chem. , 6_, 102 (1974)). All the complexes are neutral data ne with exception of uni-univalent CrdJ^Br-j-mn^O (L = 3-AMI, m = 2; L = 5- The com -ADI, m = 8). advanta The nitrates Cr (lO^NOoK • 2H2O and Cr ( L)^Brj *mH20 derivatives are monome- relativ: ric, while other compounds are polymeric. The metal and the ligands stretching modes have been assigned according I: to the literature data for the complexes of Cr(lll) with heterocyclic li- for sev gands (R.J.H. Clark and G. Natile, Inorg. Chim. Acta, 4., 533 (1970) - and oxj, D.M. Adams, "Metal-Ligand and Related Vibrations", E. Arnold, London, 1967 - C. Preti and G. Tosi, Can. J. Chem., _52_, 2845 (197^)). All the de- are repi rivatives do not seem to be co-ordinated through the v(-NH2) group be- tions 0: 1 cause the negative shifts of v(NH2) in the range 3460-3200 cm" are ab- and 7p : sent. v Cr N being ti The monomeric complexes involve unidentate N-bonded ligands ( ( ~ ring^ in the range 245-233 cm'1), the polymeric compounds bidentate bridging N- parameti 1 1 and O-bonded ligands [v(Cr-Nring) ~ 245 cm" and v(Cr-Ori ) = 330 cm" )] Am. 61,1 (R.J.H. Clark and C.S. Williams, Inorg. Chem., 4, 350 (1965) - R.J. LCAO co< Garvey, J.H. Nelson andR.0. Ragsdale, Coord. Chem. Rev., £, 375 (1968)). The electronic spectra show three bands in the ranges 183OO-152OO (vj), s,ptd ai 1 266OO-212OO (v2) and 396OO-323OO cm" (v,). The ratios \>2/ VJ are in the the cord 1 range 1.41-1.32, while the ratios Dq/B lie between 3.15 and 2.54. obtained electror electrox the expe other me ac ion r0 high va or no c force c

124 III.b.16

STWGTURE OF SOME OCTAHEDRAL COMPLEXES OP ACTIHIDE BLBiENTS 7 SEVEN-CO /i.B.Bersuker, Vict.ISpitsyn, I.Ya.Qgurtsov, £.1..Frunze, M.A.Baraga S.K. Sah Department of Quantum Chemistry, Academy of Sciences, Moldavian SSfl, Departme 277028, Kishinev, USSR In the quasirelativistic method suggested earlier for electronic The synt structure calculation of coordination compounds containing heavy atoms, a.cid hyd based on the Dirac equation (I.B.Bersuker, S.S.Budnikov, B.A.Leizeror, series hi Int.J.Quant.Chem.6,349(1972)), the relativistic effects are taken into p li^and. ' account with an accuracy up to (v/c) , where v is the electron velocity, (III), mi the MO LCAO scheme (most convenient for analysis of chemical properties origin) being preserved. Recently this method was extended to a semi- and cor>p< empirical one of the self-consistent charge and configuration (SCCC) analyses, type, which makes possible electronic structure calculations of any these coi heavy atom poliatomic system, provided there are enough spectroscopic data needed for the parametrization (Int.J.Quant.Chem.,11,N1(1977))» have the The computation results for the PtCl^" complex show explicitly the or CH-COl advantages of the relativistic calculations as compared with the noa- relativistic ones. In this paper the results of the electronic structure analysis - one havii for several octahedral complexes of actinide elements with fluorine azomethii and oxygen carried out by the semiempirical quasirelativistic method, infrared are reported. As a basis of theMQ_Jj£AOmethojiJ30 relativistic combina- tions of 40 atomic functions (2s and 2p for the ligands and 5f,6d,7s discusse< and 7p for the central atom) were chosen, the radial function parameters complexes being taken after G.Burns (J.Chem.Phys.,42,1521(1964)). Other empirical consister parameters were estimated using L.Brewer's experimental data (J.Opt.Soc. Am.61., 1101,1666(1971)). As a result of the computation the MO energies, to have j LCAO coefficients and self-consistent charges for the atoms and for the axial vos s,p,d andf configurations were obtained (theself-consistent charges for of the cc the configurations p^g sad. 9^/2* d3/2an d d5/2» f5/2an d f7/2 were obtained summarized). On the base ol° these data the chemical bonding, electron charge distribution and relative stabilities as well as electronic spectra origin are discussed. The results are compared with the experimental data available and with calculations carried out by other methods. at ion Fo.However,the iterative procedure has the advantage that rather high variations in the zero approximation matrix F introduce too small or no changes in the final matrix F.This permits self-consistent sets of force constants to be obtained in series of molecules as indicated above

TII.b 125 i/ SEVEN-COORDINATE TRAITS ITI OK MET/iL COMPLEXES OF A HEPTADENTATE LIGAND y S.K« Sahni and V.B. Rana Department of Chemistry,D.:i.College (Meerut University),Meerut (India)

The synthesis of a new heptadentate ligand, dj1sali.cylid»a«-iiijglcolinic acid hydjrazide (DSDH), has been described. The metals of first transition series have been found to fr,rm complexes with the alxaline solution of the

linand. The complexes formed by the fiction of the Tic arid DSDH on chromium (NH. (III), manganese (III), ir>r(III), •lav.neseUl), cob-alt(II), nickel (II) and cor>per(II) salts hav^ been /-isKLatod and characterised by elemental anal3rses, and by spectral, nip me tic ar.ri conductance measurements, nil these complexes are seven-coordinate; the complexes of trivalent metals have the general formula [K(DSDK)]x, vrt-y re ii = Cr, Mn, or Fe and X = Cl or Gil* COO, while complexes ^f divalent met^l ions have the formula ^_M(DSDH)] , where K = Mn, Co, i'i or Cu. The ligand acts as a heptadentate one having coordination sites at ryridine-nitrogen, amide-oxygens, azomethine-nitrogens, and deprotonated phenolic oxygen atoms. In the far

infrared region •>>( 14-py), >> (1-UO), ?.nd ^(M-TT) have been assigned and discussed. The magnetic moments are in the range observed for high-spin complexes of the respective metal ions. The electronic spectra are also consistent with the seven-coordinate nature of the complexes which appear to have pentagonal bipyramidal shape, with phenolic oxygens present on the axial positions; such a geometry is also favoured by the molecular models of the complexes which appear to have less strain in this form. 126 III.b.R.I t- FLUORINE AND OXYGEN: COMPETING LIGANDS IN TRANSITION METAL COMPLEXES R. Mattes, G. Lux, G. Miiller, H. Rieskamp and K. Mennemann Institute of Inorganic Chemistry, University of Miinster Gievenbecker Weg 9, 4400 Munster, Federal Republic ob Germany

Many transition elements, especially vanadium, molybdenum and tungsten form various oxide fluorides and anionic fluorooxo complexes in different oxidation states. Typical examples are

425 4)4Mo204F6; Cs3W2O4F7, K^O^ and 4 ^^ In each case the central atom is octahedrally coordinated to oxygen and fluorine atoms. The anions are either mono-, di-, tri- or polynuclear. The following structural principals can be derived, especially with respect to the steric arrangement of the fluoro and oxo ligands: In compounds with d° configuration of the metal oxygen prefers terminal positions. Multiple M=0 bonds can then be formed by overlap of filled 0(2p) orbitals with empty metal d orbitals, thus lowering the high effective charge at the central atoms, induced by the fluoro ligands. The high electron density in these bonds weakens the bonds to the ligands in trans positions (structu- ral trans effect), which are usually occupied by fluorine atoms. Two or three terminal M=0 bonds at the same central atom occupy mutual cis positions, because then all t_ orbitals are available for if*-bonding.

In compounds with central atoms in lower oxidation states, e.g. Mo(V), V(IV) or W(IV), terminal bonding of more than one oxygen atom is not observed. Oxygen bridging may occur as well, or solely as in W3O4Fg" (R. Mattes and K. Mennemann, Angew. Chem. Int. Ed. Engl. J_5, 118 (1976)). Here coordination polyhedra share edges occupied by oxygen atoms.

In many di- and trinuclear anions magnetic properties and metal to metal distances give evidence to the presence of metal to metal bonds.

ions, III.b.18 127 •t "COLUMNAR" DITHIOACETATO COMPLEXES OF Pd(II) and Pt(II).

O.Piovesana ,C.Bellitto ,A.Flamini and P.F.Zanazzi +) Institute of General Chemistry and +++) Institute of Mineralogy- University of Perugia-06100 Perugia. ++) C.N.R. Laboratory of Co- ordination Compounds-Montorio Romano-Rome. ITALY The wide variety of metal-metal interactions and of structural types O If) which is being found in d-d metal ion complexes with sulfur-containing ligands (J.P.Fackler,Progr. Inorg.Chem. 2_1_, 55 (1 976) )has relevant implica- tions to topics such as the localized bonding description of the M-M interactions,the factors influencing M-M bond formation etc. We have now prepared new multinuclear complexes of Pd(II),Pt(II),Cu(I) and Au(I) with the dithioacet^^J- ligand".These compouncTs~~dif fer f rom the Known- d°-dlu multinuclear complexes with sulfur ligands in several properties, e.g. the capability to exist in different forms ,with different structu- ral and spectral behavior, and, in the case of Pd(II) and Pt(II), to generate structures of_"columnarj^jtype (K.Krogman,Angew.Chem.intern.Edit. 8^ 35(1969)),with unequal metal-repeat separations. For example, in the case of Pd(II), a red compound,of ML2 composition, has been isolated following reaction of NaiPdCl. with CH,CSSH in anhydrous ether(form A). A is transformed into a green species (B) upon addition of CS- to a benzene solution of A. Both A and B give a third, red, spcies (C) upon sublimation at 190°and 10 torr. The structures of A (monoclinic space group C2/c) and B (tetragonal space group P4/ncc) have been solve'd by X-ray methods. They contain approximately square planar PdS. chtfomophores, stacking in columns,with the Pd atoms directly over each other. In A, mononuclear and binuclear units alternate along the a axis, with metal- repeat separations of 2.755 A(within the dimer) and 3.394 A(between mo- nomer and dimer).The structure of B consists of dimers only, stacking along the 4-fold axes, with CS- molecules incorporated between different columns; the intra- and interdimer Pd-Pd distances are 2.739 and 3.257 A, respectively. In both A and B, the dimers contain four bridging ligands. Significant differences are observed among the lower energy electronic transitions of A, B and C. A:17.5(sh),20.0, 23.0 and >29kK; B: 16.3, 22.2, 25.0 and>29kK; C: 19.5, 20.7, 22.1, 25(sh) and>29kK. These data, together with additional structural and spectroscOpic. ±nfocmation on the dithioacetato derivatives of Pd(II) and of the other aforementioned metal ions, will be discussed. 128 _ ')f III.b.19

Vu ABOUT TH£. COMPLEXONATES OF Pd(II) ANDPt(II).

'; A.M. Grevtsew, N.N. Zheligovskaya,L.V.Popov, V.I. Spitsyn

Moscow State University, USSR.

If the trans- Pt(NH3)2X2 (X= Cl,Br ) practically does not interact with complexones on the basis of ethylenediamine, during the

interaction of trans- Pd(NH,)2X2 with hidrochloric ethylenediamine

(En*2HCI), ethylenediamindiacetic acid (H2Z), ethylenediamintetra-

acetic acid (H4Y) and diethylenetriaminpentaacetic acid (H,-L) we

were able to separate the following complexes: PdE^IX-, H2Pd@X-,

H4Pc^X2.5H2O , H4PdLX-3H20 . The synthesis of'l^PtLX'3H 0 was

carried out, based on K2PtX4. During the interaction of Pd(OH)2

with HgL we were able to separate the complex H,PdL'5H20. The

corresponding Pt complex H3PtL>5H20 was prepared by the interaction

of H4PtLCI'3H20 with AgNO3-

1 Infrared spectra (4000-400 cm" ) and X-ray data of H.MLX'3H20 were similar, which permited to conclude that the compounds are isostructu- ral. The adsorbtion. have a band| in t' e region 1650-1590 cm-1 and 1 1750-1700 cm" for H3ML-5H20 and H4MLX-3H20 shows the existance of free and bound carboxylic groups in the complexes. Potentiometric studies water solutions of the compounds anables to obtain the ratio between quantity of coordinated andnoncoordinated carboxylic groups. 3»'

III.b.20 129

}",SPECTRAL PP.OPEPTlts- UF COMPOUNDS OF THE MCI, i K-S-R, }2 TYPE, WHERE M = Pt (II) '-/AND Pd(ÎI), P. = METHYL AND P} » PHEMYL, O-.'IP-, p-TOLYL }'j SYNTHESIS . Y. Iamamoto-, O.A. Serra1 and L.R.I'. Pitombo1 \l COMPLEXES ( 1) Institute de QuTmica - USP, CP.20780, Säo Paulo, SP, Brasil I Virgil L. ( 2) Departanento de QuTmica - FFCLRP-ÜSP, Ribeiräo Preto, SP, Brasil 'Department Tallfihasse«

Compounds of the MC12(R-S-Pj )? type where V. = Pt(II) and Pd(II), The cl F = methyl and P^ = phenyl, o-, m-, p-tolyi were synthesized and this the study c of the maci formula was confirmed by analysis. toward a v; The trans-ML0X0 complexes with Doh synmetry were characterized Soc. , £8_, • •I i. L. C 'I shown to ai by IR, Raman and H-NHR. measurements. -1 benzenoid i The observation of the symmetric Pt-Cl stretching mode at 327crr" Studies of expected tc (P.) and the asymmetric at 343cm (IR) indicated for the PtCl 2 (pms )2 the

D2j symmetry ;trans), that is also in agreement with other authors (F.J. The re S. Reed, PhD. Thesis, Univ.of Bristol, (1972) and ILL.A. Temperini, the presenc Master Dissertation IQ-USP (1974)). integrity a The spectrum of Hl-ÜMR due to the Pt-S-CH coupling presents a 7.28(8,s)) to a molecu doublet superimposed to a singlet making the appearance of three bands absorptions with intensity relations 1:4:1. The coupling constant for the cis ( structural isomers is larger for than trans isomers. The Jpt_u for the compounds analysis. of platinum(II) is 44.0 Hz confirminn 3 trans-structure (K.f-'c Farlane, J. c = 12.022( I>c = 1-67 g Chem.Soc. Dalton. Trans. 1974 , 32*). very warped Electronic spectra for the mentioned compounds were obtained directed pe coordinatio using a mull in Fluorolube and solut'ons in n-hexane and in ace te i tri le. diiminato c T| Orbital molecular diagrams were developed for the PtCl~(pi s )n arrangment of 3.08 K, and P dC10 (pms ),, whereby the electronic spectra were reasonably in agree- ment with the proposed diagrams, in this manner clarifying the electronic structure of the compounds. The shift of the ligand to metal electron transfer (LMET) transition due tu factors as complexes central atoms, different radicals bounded to sulfur atom, supplied important informations, making possible the interpretation of the data previously obtained from the palladium(II) compounds (L.P.M.. Pitorbo, Ana 1. Cherr.Acta, _62, (1972)). It was also possible to situate the phenyl methyl sulfide (pms) .2- in the followinc spectrochemica1 series: mnt < Br < Cl -pms < dtp < F" 9 _ 'HpO^oS (P. = a 1 ky 1 ) < NH, < SO, , indicating IT bonding stronger and a When t bonding weaker for aryl alky! sulfide complexes in relation to alkyl phere of ol sulfide complexes. occurs, tog coordinate •T' 130 III.b.21

1 / SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF RHODIUM(I) and RHODIUM(III) \j COMPLEXES OF THE TETRA-AZA MACROCYCLIC LIGAND, C22H2l+N4. / Virgil L. Goedken, Guy C. Gordon, and Marvin C. Weiss 'Department of Chemistry, Florida State University Tallahassee, Florida 32306 U.S.A.

The chemistry of macrocyclic ligands has largely been devoted to the study of first-row transition metals. The cobalt(III) complexes of the macrocyclic ligand C22H22NS~J £» are particularly reactive toward a variety of substrates(M. Weiss and V. Goedken, J. Am. Chem, Soc, 9_8_, 3389(1976)). The source of this unusual reactivity has been shown to arise from steric interactions of the methyl groups with the benzenoid rings(M. Weiss and V. Goedken, Chem. Commun., 531(1976)), Studies of the second and third-row transition metal complexes are expected to reveal an equally rich and varied chemistry-

The reaction of RhCl3>3H20 with the macrocyo.lji l.igri/,.dr I, .v-> the presence of CO, ethanol, and a base results .in the £.ivmatlor1 •"•f Rh2(C22H22N4) (CO)^. The lH nmr speca-mm of the fomplex f.onfirmed the integrity and symmetry of the ligand(1.77 ppm, 6(12,s); 4.75(2,s), 7.28(8,s)) and the mass spectrum yielded a parent peak correspording to a molecular weight of 64 6. The ir spectrum contained strong CO absorptions at 2008 and 2062 cm-1, not far removed from those .:f Rh2Cl2(C0)lf. An unambiguous structural assignment, among the various structural possibilities envisaged, was provided by an x-r~.y structure analysis. Crystal data: space group, PI; a = 10.385(2), h = 11. n 03(2), c = 12.022(1), a = 11.34(1), @ = 94.87(1), y = 95.28(1); Dm = 1.70, Dc = 1.67 g cm~3. As illustrated by II, the structure contains a very warped macrocyclic ligand with tEe" nitrogen lone electron pairs directed perpendicular to the N4 plane of the ligand. This allows the coordination of two Rh(I) atoms, each bound to one of the 2,'.l-]L>entane- diiminato clrelate ring's. The resulting rofacial and eolippnrt arrangment of the coordination planes leads to a Rh-Rh separation of 3.08 A, indicative of a slight bonding interaction.

RhCI3, CO EtOH, base

. II When the reaction described above is carried out under an atmos- phere of olefins in place of CO, insertion of the Rh into the N^ plane occurs, together with the reduction of the olefin, to yield five- coordinate Rh(III) alkyls of the type [(CHN)R] sti:r.ula

O III. b. 22 rJ^" 131

AQUEOUS MACROCYCLIC INTERACTIONS */ STRUCTURAL SOME SWIHE A. Anichini, R.M. Clay, L. Fabbrizzi and P. Paoletti M. Rodrigue

Istituto di Chimica Generale dell'Universita, Departament Carlos, Uni 50132 Florence - Italy Recent metal compl Recent interest in the thermodynamic interpretation of the extra- Inorg.React -stability of metal complexes with tetraraza macroeycles in com- parison with open tetramines prompted us to study by a direct crocyclic c calorimetric technique reactions of aqueous copper (II) a:.»d zinc (II) ve been des ions with some of these ligands having different ring sises. In the case of copper(II), we have found that the enthalpy of form- The condens ation of the most exothermic macrocyclic complex, 14-aneN., exceeds "cis" deriv that of the most exothermic linear complex, 2,3,2-tet,of about nenickel(II 5 kcal.mol" 2(macrocyclic enthalpy). Good agreement for the Cu(14-aneN4) + complex with respect to the linear relationship ca-1,11-diei between enthalpy of formation and energy of the d-d band of copper(II) tetragonal complexes, previously reported (L.Fabbrizzi, stereoisome: P.Paoletti and A.B.P.Lever,Inorg.Chem.,15,1502 (1976) suggests In the that the macrocyclic enthalpy depends upon formation of stronger in-plane coordinative Cu-N bonds. The solvation enthalpy does not lected foT ] appear to play any discriminating role between the coordinating in order to ability of open and closed tetra-aza ligands, in contrast to previous interpretation (F.P.Hinz and D.W. Margerum,Inorg. Chem.,13, Single 2941 (1974)). 12 aneN, and 15-aneN4 coordinate to copper(II) less and show no exothermically, probably due to a less favourable orientation of nitrogen atoms and possibly to the assumption of a cis-configuration,as fine quarte' suggested by electronic spectra. For zinc(II), the largest and most certain orii flexible macrocycle, 15-aneN^, coordinates most exothermically, presumably due to the larger size of the zine(II) ion and i*s lines are n tendency towards tetrahedral stereochemistry. raction and other hand, The correlation between macrocyclic hole and ion size has been investigated by studying the aqueous interconversion between planar nents of th< diamagnetic (yellow) and octahedral paramagnetic (blue) nickel(II) g2 = 4.415-1 complexes. Tendency to' stabilize the planar form is related to the ligand's ability to establish strong in-plane interactions. 14-aneN4 tb-s c-axis. gives solely the yellow planar species. The larger 15-aneN. gives X-ray ( an equilibrium mixture of blue and yellow species, the latter being strongly favoured by high temperatures and large ionic strengths. racemic or ,- Ni(12-aneN^)2+ exists as planar complex only in drastic conditions (No.60) ofti of temperature and ionic strength (6 M NaC104). This is the first report in which a coplanar coordination has been demonstrated for dc = 1.59; : the smallest macrocycle, 12-aneN.. or a two fo! Studie; 2,4 diketone

f*) Present The knowledge or the concecuences uf MIL ir. cor.rp_exeR o.: uiui.i; stimulate the new exploatations of compounds of this central atom.

132 TIT. ,h~?3 V/ « 'V STRUCTURAL PROPERTIES OF COORDINATION COMPOUNDS WITH SOME SYNTHETIC MACROCYCLIC LIGANDS M. Rodrigues, E. Rodrigues and J. Costamagna " L.N. Pan Departamento de QuSnica e Fisica Molecular, Instituto de Fis.ica e Quimioa d1? Institute o Carlos, Universidade de Sao Paulo, 13560, Sao Car.ios, SP, Brasil. The tc Recently, a large number of macrocyclic ligands have Keon syntho.-izcrt and their Hf(0H).2A metal complexes have been extensively studied (i,.v, Lindoy ?nd D.H. ftisch, Prep. 8H20 (h p Inorg.React. 6_, 1(1971), L.F. Ljndoy, (..hem.Soc.ita". 29, 421fl97 >)). Vwriver, tJv> •••>- nine ( h crocyclic complexes formed by condensation of metal• diamino ccvtn\fsna.r. .':1th ketonR'i o*. stable in ve been described by Curtis and co-workers (N.F. Curtis, Coord Chfim.R-v. \ 5(1^9,)). aciciic ) , The condensation of acetone with nickel-ethylenediamine complex l^auc to i;trans" sn\ (30 - 400 "cis" derivatives (2,4,4,9,11,ll-hexamethyl-l ,3,8,12-tetra-azac:'clotetr"der:a-l,8-die • are sirnilai nenickel(II) perchlorate and 2,4,4,9,9,11-hexamethyl-1,5,3,12~':c,trt\-pxr-.cyclctetrad':- that Ci~ ca-l,ll-dienenickel(.TI) percW.orate, respectively) with theoveticauy "'jroe :'.?ffST-T. and are c stereoisomers for each geometric isomer. ron spectr In the present work, electronic paramagnetic resonqrice and/or x-~ay c )1 of the Is lected for nickel (II) and copper(II) complexes /i.th some tetrsaza macr-ocycle l toruzation in order to characterize its structures and its isomers. Chern . 17 Single crystals of the "cis" complex of nickel (II) cited above r.v. rine is i 9i and show no epr signal. Crystals doped with 1% of copper(IQ shrw t~p~. • ;.rpsct^f'iper. - coordinate! fine quartet. However, the lines are .'-istorted and show an unreserve*-' "t-nrcfr of cuordim certain orientations of the external magnetic field, under hirh res^lircio't, * icvee Br", NO", i lines are resolved into nine lines each. These 7ines are due to super >.-.perf:"ne inte- of 2r = O raction and suggest an interaction wit5i the nitrogens in the maTocyrli'". ring. C-. to- taij- these other hand, spectra taken with the magnetic field in th* ac-plane permitt^ *he cyi^o obtained fc nents of the g and A tensors to be dr-termired. In that plar.s p, is given 'iy assisjnriient g = 4.415-0.247 sen 26, where Q is the archie between the external Tagnetic field rnd table using the c-axis. Symmetry is axial with the axis along the c-dir^ction. riation with X-ray data of this crystal was taken in order to see whether t.hi.~ crupnur-1. !^as a racemic or a meso molecular structure. Preliminar)' results #iv= space grou;3 Fbci (No.60) orthorhombic; a = 10.5?; b = 11.11; c « 19.14 %; V = 2250 A:> ; A^ ••• l-?9; 1633 d = 1.59; Z = 4 and suggest that the cation complex has either an inversion copter ~1500 or a two fold rotation axis. Epr results are consistent with this second possibility. Studies on complexes with ligands prepared by condensation of other ketones and 1415 2,4 diketones are in progress. 1351 (*) Present address: Departamento de Quimica, Facultad da Ciencias, 1306 Universidad Tecnica del Estado, Santiago, Chile. UI) are t

> III.b.R.2 133

,* ZIRCOKIUKJ AND COMPLEXES WITH - ALANINE ^ L.N. Pankratova , G.S. Kharitonova Institute of Nuclear Physics,Moscow State UniversityjMoscow 117234,USSR.

The following complexes: M(OH)2A2C12 . 3H20 ("i), Zr(OH)2A2Br2 . 3H20(n)

Hf(0H)2A2(N03)2 . 3H20 (ill) have been obtained by the reactions of MOClg .

8H20 (M - Zr or Hf) , ZrODr2 . 8H20 and HfO(NO3)2 . 2H2O with Cl-ala- nine ( L and D) in aqua-alcohol solutions . These complexes are white solids stable in the air , vvell soluble ir. water and methanole (aqueous solutions are acidic ) , but insoluble in usual organic solvents . IR spectra of solid state (30 - 4000 cm" ) and of H^O solutions (400-4000 cm" ) of these complexes are similar and resemble the IR-spectra of free 0L~ alanine . This indicates that 0C- alanine molecules in Zr and Hf complexes exist in the betaine form and are coordinated by oxygen atoms . These results are confirmed by elect-

ron spectroscopy of chlorine complex Zr(oi-I^) A2>C1 . 3H O . Binding energy of the Is electrons of nitrogen is 401,7 eV, v/hich is indicative of nitrogen pro- tonization . ( G.S. Kharitonovs , V.I. Nefedov , LN. Pankratova , J. Neorgan. Chem . 17 , 3134 (l?'72) ). Binding energy of the 2p 3/2 electrons of chlo- rine is 3 98.2 eV ,j'.e. Cl-ions are in the outer sphere . The frequences of un- coordinated NO" - ion have been found in spectrum (ill), but the frequences of coordinated nitratogroups were absent . These data indicate that the Cf, Br", NO~ ions are in the outer sphere (uncoordinated) . There are no bands of Zr = O or Hf * O groups in spectra (l)-(l[l), i.e. the complexes don't con- tair. these groups . The tetrameric structure proposed on the basis of the data

obtained for (l-Ill), corresponds to M4(OH)8AgX . 12H2O (op. cit.) . The assignments of son>e fundamental frequences (cm "") .are summarized in the table using (1) as an example . The listed frequences are shifted by deute- riation with normal isot-»opic coefficient .

I(2r) KM assign IfZr) Km) assign. Kir) assignment 1635 12131 1633 1210") or(NHs) ~1500 1500 moj 1112J 760 762 ^(COO*)

«»1465 ~1465 Ss(CH3) 1140 1120 667 675 1415 1415s )t (COO*) 1010 1012 610 613 o> (COO'j 1351 1351 Ss (CH3) 930 9 25 S)^ (ccN) 530 540. pr (COO'j 1306 1308 846 842 S (MOX)? 390 370 V (MO)? t. II) are temptatively explainedc

Thursday, July 21, 1977

Room A Room B

9.00 h M. Savy P . Finocchiaro 9.20 A. Sgamelotti G. Ibarra 9.40 L. Tosi K . Yamazaki 10.00 R.R. Gagné M .M. Muir 10.20 G. Toralballa S . Yamada 10.40 R. Sau H . Ioneda D. Craciunescu

11.15 S. Kirschner

Room C Room D

9.00 A.M.G. Massabni S.A. Abbassi 9.20 H. Schumann H.A.S. Andrade 9.40 J. Chacko R.E. Sievers 10.00 A. de Oliveira K. Bächman 10.20 M.J.S. Nastasi > R.C. Mehrotra 10.40 K. Satyanarayana 1 L.B. Zinner (V Thursday, July 21, 1977

Room A Room B

14.00 h W.E. Newton W. Preetz 14.20 W.P. Griffith S. Bunel 14.40 H. Schraidbaur C. Preti 15.0.0 G. Marcotrigiano G. Eichhorn 15.20 J. de O. Cabrai

16.00 K.N. Raymond F. Tarli 16.20 D. oraciunescu I.B. Baranovskii 16.40 A. Scozzafava A. Syamal J. Reedijk

17.00 H.M.N.H. Irving

Room C Room D

14.00 R. Poilblanc L.R.M. Pitombo 14.20 R.J. Mureinik A.J. Curtius I 14.40 U.F. Schuchardt A. Jensen 15.00 I.V. Berezin A.C.S. Costa (0 15.20 H. torn Dieck H. Molina •o A.K. Yatsimirsky

16.00 P.H. Rieger K. Ueno 16.20 G. de Oliveira 7J. Chatt mm 16.40 N. de Araûjo M.H.A. Sekkina

(u.w. : 134 11.26

PROPOSAL FOR A NEW TYPE OF FUNDAMENTAL REACTION : THE OXYDATIVE ADDITION ON TWO , t METAL CENTERS R. Poilblanc Laboratoire de Chimie de Coordination du CNRS, BP 4142, 31030 TOULOUSE CEDEX, France

Extensive work on the reaction of Fe2(p-SR).?(C0)fi L (K. FauVeT., R. Mathieu and R. Poilblanc, Inorgwg. . Chem. _15, 976 (1975)) complexecomplexess' with Lewis acids, like H T,, SSOC . HgCl2 (S. Arabi, R. Mathieu and R. Poilbianc, u.w.) recently extended to some easel of related cobalt and ruthenium complexes,give us convincing examples of addition "on" the metal-metal bond. Such a reaction, exemplified by the case of [Fe(ySMe)(COJ-PMepPhJ + + H •+ [Fedj-SMeHCOUPMeoPh J2H , which keeps almost unchanged the hinged geometry (J.-M. Savariault, J.-J. Bonnet, R. Mathieu and J. Galy, C.R. Acad. Sc., Ser. C, 0G0 (1977)) of the starting complex, can be considered as an oxydative addition. As an ex- tension, we are inclined to consider reactions like : [Fe(y-SR)(C0)3]2 + C(CF^)-C(CF,) -* (Fe(p-SR)(C0)3]2C(CF3):'C(CF3) as oxtjdatxvt addltiom on two metalHtomi, eacn of them loosing one electron, and therefore the possibility of contracting a metal-metal bond (J.L. Davidson, W. Harrison, D.W.A. Sharp and G.A. Sim, J. Organomet. Chem. 46, C47 (1972) - R. Mathieu and R. Poilblanc (u.w.)).

Conversely, we investigated the possibility of oxydative addition on two non bondzd metal atoms. The recently prepared hinge-shaped dinuclear complexes [ir(p-SR)(CO)LL (J.-J. Bonnet, J. Galy, D. de Montauzon and R. Poilblanc, Chem. Comm. 000 (1977)) pro- vide a suitable/testing situation. In the case of L = CO, in the course of the inves- tigation of the; reactioi uu^i. i VnM witf4 triI - nuclear species; (Ir(y-SR)),(C0)(Ir(vi-SR)),(C0)r(PMe,)c(PMe,)o, witwithh ononee C COO bridgebridgedd liganligandd anandd onone ever veryy short Ir-Ir distance (J.-J. Bonnet, P: KalCk and R. Poilblanc (u.w.)). In a similar way, reaction with hexafluorobutyne, as an electrophilic ligand, also giv(es, as shown by molecular weight and spectroscopic data, trinuclear species (D.' de Montauzon and R. Poilblanc (u.w.)). Preliminary X-rays investigations (J. Devillers and J.-J. Bonnet (u.w.)1.demonstrate a symmetrical fixation of the alcynes acting as a bridge between two Ir atoms (I).

Reactivity of 02 and TCNE has been comparatively investigated (A. Maisonnat and R. Poilblanc (u.w.)). Dioxygen gives (Ir(y-StBu)(C0). 02) compounds as expected for an individual addition on each Ir atom.- With TCNE, on the contrary, NMR, infrared and molecular weight data are consistent with a 1:1 adduct (Ir2/TCNE = 1) for which a symmetrical dinuclear structure Ir**-Ir^ is proposed (II). Finally evidence for a . dissociative and symmetrical addition of dihydrogen in a 1:1 dinuclear adduct (III) is presented.(A. Maisonnat, A. Thorez and R. Poilblanc, to be submitted). Therefore a rule is discussed, from consideration of the cases (I), (II) and (III) from which symmetrical oxydative additions on pairs of metal atoms are accompanied by the formation of a Irli-Ir11 metal-metal bond. New speculations on the activation of molecules, on the bimetallic catalysis arid on the relations between heterogeneous and homogeneous catalytic phenomena follow at once.

(u.w. : unpublished works) 135 IV 11.27

I OXIDATIVE ADDITION REACTIONS OF PALLADIUM(II) COMPLEXES R.J. Mureinik, and E. Pross Department of Inorganic and Analytical Chemistry, Hebrew University of Jerusalem, Jerusalem, Israel. The kinetics and mechanism of the oxidative addition of chlorine to some square- planar palladium(II) complexes has beeen investigated in aqueous acid solution by the stopped-flow technique. The reaction proceeds in two stages, in the first of which oxidation occurs Tapidly yielding an octahedral palladium(IV) aquo complex (1) which subsequently undergoes slower anation (2).

Cl2 PdLt»Cl(H2O) + Cl" CD

PdMCl)(H20) Cl" H20 (2)

The oxidation step (1) is first-order in chlorine and first-order in palladium complex, but the observed first-order rate-constant is a complicated function of the _ composition of the reaction medium.for the reaction of PdCl 2 a+b obs c+d[Cl- whereas for PdenCl2, e»f[Cl~] obs

These rate laws are interpreted in terms of the participation in the oxidation step of aquo complexes formed by hydrolysis of the mother compounds. The observed mechanisms are compared with those proposed for the oxidative addition reactions of halogens to related platinum(II) complexes (L.I. Elding and L. Gustafson, Inorg. Chim. Acta, 1£, 165 (1976)). Stability constants for the palladium (IV) species are reported. electronic spectra origin are discussed. The results are compared with the experimental data available and with calculations carried out by- other methods.

136 11.28

JIFFERENT INTERMEDIATES FORMED IN THE OLIGOMERIZATION OF OLEFINS ON PALLADIUM(0)-AND PALLADIUM(II)-COMPOUNDS

P. Binger, P. Faria dos Santos Filho and U. F. Schuchardt

Department of Chemistry, University of Campinas, S.P. C.P. 1170 - 13.100 - Campinas, S.P., Brasil

The palladium-catalyzed dimerization of simple olefins (i.e. ethylene, propene, butene) involves a palladium(II)-hydrogen-bond, in which two olefins can insert. Under 3-hydrogen abstraction the linear dimeric olefin is finally formed. In contrast, palladium(0)-compounds in aprotic solvents will not react with these olefins up to 200°C, but strained-ring olefins (i.e. cyclopropenes, methylenecyclopropanes) cyclodimerize or cyclotrimerize under relatively mild conditions in the presence of palladium(0). Palladium(II) polymerizes these olefins instead, continuously inserting into a once formed Pd-C-6-bond and building up straight-chain polymers. The mechanism for these oligomerization reactions will be given, indicating the palladium- intermediates involved. This distinction can be extended to butadiene- and allene- oligomerization. Butadiene is usually dimerized to 1,3,7-octatriene by palladium-catalysts, a process which proceeds through intermediate palladium(II)-hydride species. We found that this reaction is totally suppressed in the presence of palladium(0)-catalysts under aprotic conditions, the well know cyclodimers, 3-vinyl-cyclohexene and cyclooctatetraene-1,5, being formed instead. Also allene, which is polymerized by palladium(II)-compounds under catalytic conditions, can be oligomerized by palladium(0) in aprotic solvents, forming cyclotrimers, -tetramers and -hexamers. to me metal

11.29 137 t LIGAND EFFECTS AND BASE CATALYSIS IN THE KINETICS OF DIRECT PALPATION REACTIONS ItY.gerezin. A.K.Yatsirairsky Department of Chemistry, Lomonosov State University, H. BJ II7234, Moscow, USSR ffhe formation of a metal-carbon bond by direct substitution is Instj a general and extensively investigated way of homogeneous catalytic Theoc activation of C-H bonds (see e.g. G.W.Parshall, Accounts Chem.Res., 1.Z39 (1970); ibid.,£, 113 (1975)).We have studied the kinetics of In tl such process as illustrated by the following reaction: trans

2Pdl2Cl2- (L-H)PdCl2Pd(L-H) - 2L - 2HC1 (i) bis-c where L - azobenzene and L-H - ortho-raetallated azobensene. Reac- dinai tion (I) is a first-order reaction (at 25° and 0,02M NaClO. in EtOH tions containing 10% by volume of CHC1,) and is sharply accelerated in seque the presence of sodium carboxylates and other bases. In the carbo- comp] xylates series this effect is increased with the increase of car- risai boxylate anion basicity thus indicating the existence of general polyi base catalysis in reaction (i). However, for strong bases, such as the I Et,N or OH", the reaction rate reachs a limiting value wich is in- isocj dependent of bqth the nature and the concentration of a base. Unex- (DAD) pectedly base catalysed reaction was found to be appreciably acce- (CN). lerated by chloride anions, while chloride had no effect on reac- acti-< tion (1) in the absence of added bases. The possible explaination meta] of such a behavior is that in the presence of strong bases the rate and i determining step due to C-H bond attack is replaced by ligand sub- stror stitution. Other possibilities and general mechanistic aspects of lyti< reactions of Pd(II) with C-H bonds are also discussed. to metal distances give evidence to the presence of metal to 22.2, metal bonds. toget] dithic ions,

138 11.30 COM ^/REACTIVE METAL(O)-BIS(CHELATES) OF CHROMIUM, MANGANESE, IRON, PRE COBALT, NICKELj COPPER. A.K H. Bruder, H. torn Dieck, A. Kinzel and M. Svoboda Dep 117 Institut fur Anorganisohe Chemie der Universitat Frankfurt, Theodor-Ster-Kai 7, 6ooo Frankfurt 7o, F. R. Germany. cor diu In the presence of N-substituted 1,4-diazadienes-(1,3) (DAD) most tun transition metal ions are easily reduced to give tetracoordinate bis-chelates of general type (DAD)_Me(O). The unusually low coor- dination number (for metal up to Co(0) gives interesting nwe reac- it tions as well as the very low first ionization potentials as a con- rat sequence of exclusive N-coordination. With several of these new complexes types diene dimerisations and trimerisations, cooligome- risations with alkynes, alkyne oligomerisation and olefin or alkyne spe polymerisations are observed. The reactivity strongly depends on low the N-substituents (Cr, Fe, Ni) 1 (DADKFe reversibly adds CO; ace isocyanides and carbenes (from diazo compounds) are added as well.

(DAD)2Ni adds O_; oxidative additions are numerous, e.g. with NOC1,

(CN)2 or CF,X and the iron compound or with electronically non- activated CH bonds in the Ni case. Thermal decomposition to give Mea metal and free ligand is observed for Cu(DAD)2 at RT. The magnetic pie: and electron spectroscopic properties of these new pseudotetrahedral, med. strongly coloured complexes are discussed and related to their cata- lytic reactivity. transitions of A, B and C. A:1 7 . 5 (sh) , 20. 0, 23.0 and >-iyKK; a: IO.O, 22.2, 25.0 and>29kK; C: 19.5, 20.7, 22.1, 25(sh) and>29kK. These data, together with additional structural and spectroscopic. information on the dithioacetato derivatives of Pd(II) and of the other aforementioned metal ions, will be discussed.

II.R.5 139

COMPLEX FORMATION AND OXIDATIVE COUPLING OF ARYLOLEFINS IN THE PRESENCE OF PALLADIUM(II) ACETATE

A .IS, .Yatsimirsky, r A. D. Rvabnv w. Department of Chemistry, Lomonosov State Universi.ty, II7234, Moscow, USSR The kinetics of oxidative coupling of some arylolefins (01) to corresponding I,4-diaryl--I,3-butadiens in the presence of palla- dium II) acetate has been studied in acetic acid containing sodi- um acetate from 0 to 1 M. Taking into account the following equi-

libria: 2Pd5(0Ac)6 + 6HaOAc s^ 3Na2Pd2(0Ac)6; Na2Pd2(0Ac)6 + 2Ka0Ac

s=6 2»a2Pd(0Ac)4 (R.N.Pandey,P.M,Henry, Can.J.Chem. ,52.,i24I (1974)), it can be shown that the rate expression for oxidative coupling is: i-4 rate = kt[Pd3(OAc)^] [oi] + kd JNa2Pd2(0Ae)5(01)] , where kd 2,'I.'I0 / u M-I---I - ** I5,6kcal/mole,AS*= -23,Oe.u.) and k^= 4,5 10 = 2I,9kcal/mole,^S*=i -9,4e.u.) at 25°. The monomeric Pd(II)

species, Na2Pd(0Ac). is unreactive. It was found that Pd,(0Ac)^ at low concentrations (4.10" M) undergoes spontaneous depolymerisation 10 2 according to equilibrium Pd5(OAc)6 =£ 3Pd(OAc)2, K= 2,7* IO" M .

This type of monomeric species, Pd(OAc)2, was shown to fora a DT-complex with an olefin.However, in this case, in contrast to dimeric species, 3T-complex is unreactive in oxidation reaction. Mechanistic implications of results obtaind and the role of 7T-co»- plexes in palladium(II) catalysed olefins reactions in acetate media are discussed. 140 11.31

MAGNETIC RESONANCE STUDIES OF THE TRIHYDROXOVANADYL(IV) ION

W. c. Copenhafer and P. H. Rleger Department of Chemistry, Brown University Providence, Rhode Island 02912, U. S. A.

Vanadium(IV) has been shown to exist as a trihydroxo complex ion in strongly basic aqueous solution. Analysis of the electron spin resonance and optical spectra suggested that the species differs 2+ from the pentaaquovanadyl cation, VO(H2O)5 , by the ioniz&tion of three equatorial aquo protons [M. M. Ianauzzi and P. H. Rieger, Inorg. Chem. , IU^, 2895 (1975)]. Analysis of the esr linewidths gave results consistent with the above interpretation, but also indicated an unusually large equatorial aquo and/or hydroxo proton hyperfine coupling [M. M. Iannuzzi, C. P. Kubiak, and P. H, Rieger, J. Phya. Chem., j[0, 541 (1976)]. Proton, deuteron, and oxygen-17 magnetic resonance studies of solvent water in solutions of VO(OH).(H 0) ~ have now been carried out. Deuteron exchange between the anion and solvent water is fast. The rate constant and activation parameters-- k <8 4 10 6 D s 1 H 1 298298 " <8*4 * 10~~6H°H°D~~]] ~ y * * - A0 ± 2 kJ mol"" , AS* - 22 ± 7 J mol K~ —were determined from ^-nir linewidth measurements of 99% D-0 solutions, corrected for non-kinetic relaxation contributions using relaxation times computed from esr data. A mechanism involving deuteron transfer from an equatorial aquo ligand to hydroxide ion is postulated. The 'H-nnr and esr data were used to predict 2H-nmr linewidths which are in good agreement with experimental values. Oxygen exchange between VO(OH)_(H_O) ~ and solvent water is slow on the 170-nmr time scale; a lower limit of 7 * 10~ s is calculated for the lifetime of an oxygen atom in the first coordination sphere at 65°C. The experiment was limited by the low solubility of the trihydroxovanadyl ion, oa. 2 mM at 25°C; the low solubility also precluded measurement of ^H, 2H, or l70 contact shifts. Dondino weaker for ary] alkyl sulfide complexes in relation to a y phere of ol< sulfide complexes. occurs, tog( coordinate ]

U.R. 6 141 A\F t

^ PHYSICO - CHEMICAL CHARAüjHsTICS: OF CADMIUM FORMATE. j^E.S.C.A. U M. M. Abou Sekkina and ".E. Morsi c/î M. Savy*, S Tanta University, Tanta, Egypt, A.R.E. "C.N.R.S., 1 Facultés Ur Electroniqi The major goal of the present investigation is to understand the mechanism of water loss on heating cadmium formate dihydrate. This was performed by Specin using x - ray diffraction, infrared absorption, thennograviraetric and previously differential thermal analyses in the selected temperature range of 20 - 6009C. (1976)) by c oxygen redt 111 The obtained results were discussed and a mechanism was put forward including Fe in th a stepwise water loss. The existence of strong endothermic peaks rather than A more exothermic one were also performed ;-orrespond ing ro water loss and phase trans- using infor formation in the investigated temperature range. been detect chemical st Two or Fermi level visible on The F such fine intensity ( canyinterp of a mixtu levels, no peaks are existing th these are following The mo which the 0 trons being me reaction aescriDea acove is earned out unaer an atmos- phere of olefins in place of CO, insertion of the Rh into the Ku plane occ-urs, together with the reduction of the olefin, to yield five- coordinate Rh(III) alkyls of the type [Rh(CHN)R]

4 ,<• 142 III.a.16

?E,S.C.A. INVESTIGATIONS OF IRON PHTHALOCYANINES (MONOMER, DIMER and POLYMER) ELECTRON € M. Savy*, S. Maroie and J. Verbist COBALT(II)

*C.N.R.S., Laboratoire d'Electrolyse, F-92190 Bellevue, France. F.Cariati, Facultes Universitaires Notre-Dame de la Paix, Laboratoire de Spectroscopie Electronique, B-5000 Namur, Belgique. Institutes CNR Labors Specimens of iron phthalocyanines (polymer, dimer and monomer) have been previously examined (A.J. Appleby, J. Fleisch and M. Savy, J. Catal. 44, 281 The _Xr_ray_ (1976)) by optical and Mbssbauer spectroscopy. Electrochemical measurements for (CoPc) and oxygen reduction showed the highest activity occurred for fivefold coordinated base of tt Fe in the intermediate spin state. riati, D.C A more thorough investigation of the surface has now been made by E.S.C.A., F.Cariati, using informations from both core and valence photoelectron peaks. Oxygen has teresting been detected on the dimer and polymer surfaces (not on the monomer) and the The result chemical state of iron has been studied from the 3s and the 2p,,, - 2p,,o levels. lectron sj stand the Two or three d bands have been observed in the valence band beginning at the are partic Fermi level. Spectra differ widely from one sample to another. A sharp peak is models. visible on the dimer at an energy value close to 0 2p. The values The Fe3s levels fail to show any multiplet splitting on the monomer, while delocalizc such fine structure is observed for the dimer. From the position and relative ding the n intensity (S.P. Kowalczyk, Thesis, Berkeley (1976)) of individual peaks, this V^ III gands towc canyinterpreted as being due to photoemission from Fe LS in the monomer, and following of a mixture of Fe111 IS and Fe111 HS in the dimer. While with the 2p 3/2 {high spir levels, no satellite peaks can be seen on the monomer spectra, intense satellite The BSR s{ peaks are observed on the dimer (less pronounced on the polymer). From the try and tt existing theories (S. Asada and S. Sugano, J. Phys. Soc. Japan, _41, 1291 (1976)), ly localis these are characteristic of shake up charge transfer transitions 0 2p 3d(eg) The values following the monopole selection rules. indicate t The most active sample is corresponding to a more covalent Fe-Og bond in cle plane, which the 0 2p orbitals are close in energy to the 3d(e ) level, unpaired elec- the equate trons being distributed on bonding and antibonding Fe-Op orbitals. raation of rent packi The extens complexes some of th nitrogen d I (*) Present

III.a.17 143 ^ ELECTRON CHARGE DENSITY AND BONDING PROPERTIES IN PHTHALOCYANINATO FORMATION A.r> COBALT(II) AND ITS ADDUCTS - A SPECTROSCOPIC INVESTIGATION A. Gamier e F.Cariati, G.Mattogno, F.Morazzoni and A.Sgamellotti DEPARTEMENT Institutes of General Chemistry, Universities of Sassari, Milan, Perugia. U.E.R. DE ME CNR Laboratbry of Theory and Electronic Structure, Rome (Italy) The properti ami no acid r The JC-ray photoelectron (ESCA) spectra of phthalocyaninatocobalt(II) our knowledg (CoPc) and its adducts CoPcL and CoPcL,, where L is a nitrogen donor very limited between cupr base of the type pyridine, 3-methylpyridine, 4-methylpyridine (F.Ca comp_iexation riati, D.Galizzioli, F.Morazzoni and C.Busetto J.C.S.Dalton 556(1975); dTnate bonds absorption a F.Cariati, F.Morazzoni and C.Busetto J.C.S.Dalton 496(1976)),yield in Homopolypept teresting information on the electronic properties of these compounds. lysine) and on pH (A. Ga The results, related to those obtained by vibrational spectroscopy, e Comm., in pr lectron spin resonance and thermogravimetric measurements help under with the met indicate, th stand the nature of the bonds in the phthalocyanine complexes, which and two oxyg are particularly important in the field of catalysis and as biological two water mo 11 two addit models. formed. Four the corners The values of the binding energies for Co3s and Nis imply an extensive CD data. delocalization of the charge on the whole mscrocycle inclu On the other coordi nates ding the metal atom. The nitrogen bases also behave as 1V acceptor la. CD patterns gands towords this macrocycle. The 1Y back-donation decreases with the peptide - ni at least, of following order: mono-adduct (low spjLn), bis-adduct and mono-adduct phenolic gro (high spin). The ESR spectra show that all the above compounds have an axial symme try and that, in the low spin complexes, the unpaired electron is main ly localized in the d 2 orbital of the metal atom. de rmations The values of the J[R_j£r-equencies relative to the °N_CO-N f° indicate that in CoPc and CoPcL2 the cobalt atom lies in the macrocy cle plane, while in the mono-adducts the metal atom is dispaced out of the equatorial plane. The results lead to the conclusion that the for mation of the mono-adducts at high and low spin is mainly due to diffe rent packings in che crystal lattice. The extension of the spectroscopic investigation to the phthalocyanine complexes of the metal of the first transition series can explain why some of these compounds, for istance CuPc, do not form adducts with nitrogen donor bases. 2,4 diKetones are in progress. 1351 (*) Present address: Departamento de Quimica, Facultad de Ciencias, 1306 I Universidad Tecnica del Estado, Santiago, Chile. I

aS ,,^144 Ilia.18 £ MODE IS FO FORMATION AND STRUCTURE OF Cu(11)-POLY(L-AMINO ACID) COMPLEXES IN AQUEOUS SOLUTION J/ R. R. Gagn( A. Gamier and L. Tosi Department ' DEPARTEMENT DE RECHERCKES PHYSIQUES, Universit§ Pierre et Marie Curie, Paris, France U.E.R. DE MEDECINE ET BIOLOGIE HUMAINE, University Paris XIII, Bobigny, France Pasadena, < The properties and mode of action of metalloproteins depend to a large extent on the Numerous c amino acid residues which function as the binding ligands for the metal ions. Yet, our knowledge of the coordination sphere of the metal in copper proteins is still physiologies very limited. In order to gain some insight into the specific type of interaction between cupric ions and amino acid residues we have undertaken the study of Cu(II) about Cu in • complexation to polypeptides containing side chain groups capable of forming coor- dinate bonds.'This investigation has been carried out by means of potentiometric, Several nov< absorption and CD measurements. Homopolypeptide chains containing nitrogen ligands like poly(L-arginine), poly(L- pared and th lysine) and poly(L-ornithine) bind to cupric ions in a two step process, depending on pH (A. Gamier and L. Tosi, Biopolymers 14, 2247 (1975); Biochem. Biophys. Res. complex, 1^, Comm., in press). At pH lower than 8 all three polymers form a first complex(I) with the metal when two protons per cupric ions are released. As spectrometric data structure) fi indicate, the symmetry of this complex is square planar with two ami no-nitrogens and two oxygens of water molecules at the corners of the coordination square and two water molecules in apical positions. At pH higher than 8 and up to pH 10.5 or 11 two additional protons per cupric ion are removed and a second complex(II) is formed. Four nitrogen atoms (two from amine and two from peptide groups) lie at the corners of the coordination square in complex II as shown by absorption and CD data. On the other hand, up to pH 8, the hetero polymer poly(L-lysine, L-tyrosine) coordinates to copper(II) after loosing four protons per metal ion. Absorption and CD patterns show that this complex-like complex II - contains two amino -,and two peptide - nitrogens lying at the corners of the coordination square. However, one at least, of the apical positions is filled by an oxygen atom of the deprotonated phenolic group of tyrosine.

complex whic depending on will be disciu hemocyanin a 1351 1351 930 9 25 v< (ccH) 530 540 pr (COO*) 1306 1308 846 370 V(MO)? I 842 S (MOX)? 390 I

„? III.a.19 .ir .iAy~ 145

^' '•

j MODEUS FOR COPPER PROTEINS SOME NEW C

y R. R. Gagne", J. L. Allison, C. K. Koval, and T. S. Smith J. F. Vil3 x' Departmeni Department of Chemistry, California Institute of Technology Bedford Pe

Pasadena, California, U.S.A. h series c synthetize Numerous copper containing proteins rely on the formation of Cu-O, bonds to effect of IR, elc

physiological activity. As yet little is known of the ligand or electronic environment The compoi as Cu(nuc] about Cu in these proteins, several of which contain two Cu atoms in the active site. adenosine from the ] Several novel mononuclear and binuclear complexes, e.g., 1 and 2, have been pre- bonding, 1 Electronic pared and their redox properties and structures examined in detail. The carbonyl 16,000 to 12,000 cm" complex, 1^, represents the first example of a fully characterized (including X-ray coordinate spectra wi structure) five-coordinate Cu(I) complex. Species 2 is a mixed-valence, Cu(I)Cu(H) data was c and are ir ferromagne spin coup]

F\/ A

complex which is apparently delocalized at 25°C, but localized at low temperatures, depending on solvent conditions. The electrochemical redox properties of 1^ and 2 will be discussed in reference to oxygen reactions of the copper containing proteins hemocyanin and tyrosinase. I

•r 146 III.a.20

CRYSTALLOt SOME NEW CU(II)-NUCLEOSIDE COORDINATION COMPODNDS

J. P. Villa and Harold C. Nelson and G. Toralballa Robert Bai Departmeir Department of Chemistry, H. H. Lehman College of the City University of New York 90007 Bedford Park Boulevard West, Bronx, New York 10468 U. S. A. It h. A series of four new coordination compounds of Cu(II) and nucleosides was synthetized and the spectral and magnetic properties were elucidated by means Pt(en)Cl2 of IR, electronic, EPR and static magnetic susceptibility measurements. order to The compounds were isolated from neutral to basic solutions of the components prepared as Cu(nucleoside)(OH)'XH2O, where for cytidine and xanthosine x « 2; for platinum- adenosine x = 0.5 and for inosine x • 1. Coordination sites are postulated from the IR spectra; particularly interesting is the presence of carbonyl technique bonding, hydroxyl bridging and absence of ribose involvement in the coordination. [Pt(en)(5 Electronic spectra for these compounds had the d —*• d band in the region of 16,000 to 14,000 cm"* with a low energy shoulder in the region of 14,000 to guanosine 12,000 cm"1, which can be assigned to a tetragonally distorted octahedral bond betw coordination. This symmetry was corroborated by the characteristic EPR spectra with gz > g in the expected range. The magnetic susceptibility [Pt(en)(5 data was obtained from room temperature to 15°K at different magnetic fields the N(3) and are interpreted as originating from lattice cooperative phenomenon of ferromagnetic character. Finally, the Zero Field Splitting D value (from possible spin coupled tetragonally distorted systems) was also obtained from EPR. I (u.w.

>v ' >•h*A• III.a.21 147

CRYSTALLOGRAPHIC STUDIES ON PLATINUM-NUCLEOSIDE AND PLATINUM-NUCLEOTIDE COMPLEXES. ON THE I. Robert Bau, Robert W. Gellert, Susan L. Miles and Samuel Louie COMPLEX £ D. Cracit Department of Chemistry, University of Southern California, Los Angeles, California 90007 *Departme drid, Mac It has been suggested that the anti-tumor properties of cis-P^ **Departn Pt(en)Cl2» and similar compounds may be related to their ability to bind DNA. In order to get more information at Pt-DNA interaction at the molecular level, we have some new prepared and studied the three-dimensional structures of a number of simple was appre platinum-nucleoside and platinum-nucleotide complexes with X-ray diffraction quencies. techniques. In this report, we summarize results on [Pt(en)(guanosine)2] > ted by th 2 [Pt(en)(5'-IMP)2] ", and [Pt(en)(5'-CMP)]2 (en = NH2CH2CH2NH2). In [Pt(en)- I.H.B. guanosine)2] and [PtfenHB'-IMP^] ", the primary mode of bonding is a covalent raed on an bond between the platinum atom and the N(7) atom of the purine ring, while in discussed [Pt(en)(5'-CMP)]2, the nucleotide is coordinated to two different Pt atoms (through and (PtCl the N(3) atom of the pyrimidine ring and through a phosphate oxygen atom). A Quinoline possible mode of Pt-DNA binding is suggested based on these structural results. quinoline

efffects; I I (u.w. : unpublished works)

V" M 148 III.a.R.4 / ON THE I.H.B. (INTERMOLECULAR HYDROGEN BONDING) IN 3OME NEW QUINOLINIUM COMPLEX D. Craciunescu*, A. Doadrio*, B. Sosa**. *Department of Inorganic Chemistry, Faculty of Pharmacy, University of Ma- drid, Madrid-3, Spain. ••Department of Chemistry, "Simon Bolivar" University, Caracas, Venezuela.

The strength of the I.H.B. (Instermolecular Hydrogen Bonding) in - some new quinoline tetrachlorocuprates (II) an.d hexachloroplatinates (IV) - was appreciated by the displacement of the v>N-H bands towards littlest fre quencies. , ~~ It seems that there is a relation between the values of QN(calcula ted by the M.O. Huckel's method) of the quinolines, and the increase of the I.H.B. Results of the antitumour assay of the quinolinium salts tperfor- med on animals bearing the established L 1210 and P 388 tumours) were also discussed in connection with the "salt" structure of the new (CuCl4)(LH)2 and (PtCle)(LH)2 complexes. The following quinolines (L) were used: Quinoline; 1-Methylquinoline; 2-Methylquinoline; 6-Methylquinoline; 8-Methyl quinoline; 2,6-Dimethylquinoline; 2,8-Dimethylquinoline. All of the (^tClg)2" complex salts produce "marginal1 antitumour — Effects; (CuCl^)2- salts were toxic even at doses of 25 mg/Kg. I I

n III.a.22 149 6 REACTIONS AND STRUCTURES OF SOME OXO- AND SULFIDO-BRIDGED OSMIUM AK MOLYBDENUMJVJ DIMERS. W.E. Newton, J.W. McDonald and J.H. Enemark W.P. Grif:

Charles F. Kettering Research Laboratory, Yellow Springs, OH 45387 Inorganic U.S.A. and Department of Chemistry, University of Arizona, threat Bri1 Tuscon, AZ 85721, USA The use o: The molybdenum-containing site(a) in enzymes interacts since l86i with the substrate and appears to be monomeric in nature. un saturate

However, all such reasonably characterized molybdoenzymes Biochim. ] J. Chem. i contain two molybdenum atoms per mole. Similarly, many membrane i molybdenum complexes used as enzyme models exist as phenols (V

dinners but are believed to cleave to produce catalytically reaction c with £-dii active monomers. Our studies of the reactions of 0s02I$>y2 a 2+ [Mo_0 S,._ ,] cores are directed toward elucidating the the polyme

pathways by which these bridged systems may be modified which is 1 micrograph or cleaved. Three distinct types of reaction occur: (a) gallic and substitution of bridging and/or terminal oxo groups with the •D-catechin

structure remaining intact; (b) bridge modification reactions; these spec

ana (c) bridge cleavage to produce monomers. The last reaction The oxo-br and acid m may remove either bridging oxo groups to produce pentacoordinate D.H. North oxomolybdenum(V) monomers or all oxo groups to produce of rutheni hexacoordinate molybdenum(V) monomers. Such bridge cleavage manner ana osmium com reactions may be important in both the natural and model

catalytic systems. A critical feature of all these reactions

is the requirement for sulfur on the incoming reagent.

Selective substitution with oxygen-18 in the bridge and/or

terminal positions has allowed the various stretching vibrations

of these cores to be assigned. Several of the products have

been structurally characterized by X-ray analyses. I

\ 150 III.a.23 OSMIUM AND KUHffiNIUM COMPLEXES AS TISSUE FIXATIVES ' NEW 0RGA1 W.P. Griffith, J.P. Hall and A.J. Nielson PR0PERTI3 H. Schmit Inorganic Chemistry Research Laboratories, Imperial College, London SW7 2AY, Britain. Institute Arcisstri The use of (OsOi,) for tissue staining and fixation has been known since 1865. For membrane fixation at least, the olefinic double bond in Organogol unsaturated phospholipids is "probably the primary site of attack (J.C. Riemersma, pounds, 1 Biochim. Biophys. Acta, 1^2, 718 (1968); B.J. Collin, J. Jones and W.P. Griffith, most kin< J. Chem. Soc. (Dalton), 1094 (197*+))• In some plant cells, in addition to like oxy< membrane fixation, there is evidence of strong interaction of OsO,, with £-dihydroxy great del phenols (W.C. Mueller, C.H. Beckman, Can. J. Bot., £4, 2074 (1976)). We find that the unusi 7, 351 (1 reaction of OsO,, (I), of OsO,, and pyridine (II) and of trans-K2[0s02(0H\ ] (III) For possJ with £-dihydroxyphenols (L being the ligand di-anion) gives respectively (OsOL2) 2 - n' catalytic OsO2Lpy2 and [OsO2L2J . The latter two species contain a trans 0»0s=0 unit; the polymeric species probably contains 0 - Os - 0 - Os chains and it is this faces arc which is likely to be responsible for the high-density image in the electron Chem. In1 micrographs. The phenols used were catechol, substituted catechols, pyrogallol, program, gallic and digallic acids, and naturally occurring plant cell phenolics such as vestigatt D-catechin, quercitin, coumarin and caffeic acid. Structures and properties of methanide these species will be reported. 6 + The oxo-bridged trimeric cation [RUJO^NHJ).,<,] , ruthenium red, reacts with pectins R2P and acid mucopolysaccharides to stain specific areas of tissue (D.E. Hanke and \. D.H. Northcote, Biopolymers, 14., 1 (1975))- Attempts to prepare the osmium analogue of ruthenium red give a trimeric nitrido bridged species which stains tissue in a manner analogous to that of ruthenium red. Structural investigations of this new R osmium complex and of related species will be reported. k\

R'

The struc technique For a mm which COB; in chryso I

lx'I.a.24 151

'NEW ORGANOGOLD COMPOUNDS: SYNTHESIS, STRUCTURE AND SOME PHARMACOLOGICAL PROPERTIES. H. Schmidbaur. H.-J. FUller, 0. Gasser, J.R. Mandl and A. Wohlleben Institute for Inorganic Chemistry, Technical University of Munich Arcisstrasse 21, D 8000 Munich, Germany. Organogold complexes have recently become an important class of com- pounds, because the low coordination number of this noble metal makes most kinds of mechanistic investigations particularly easy. Processes like oxydative addition and reductive elimination can be followed in great detail at these model compounds, and have been shown to include the unusual oxydation state +11 in certain systems. (J.K. Kochi, ibid. 7, 351 (1974); H. Schmidbaur, Accounts Chem. Res. 8, 62 (1975)). For possible practicals uses, the physiological properties, the catalytic activity, and the thermal decomposition to form gold sur- faces are tested under various conditions. (H. Schmidbaur, Angew. Chem. Int. Ed. Engl. 1j?, 728 (1976)). As part of a relevant program, the following types of organogold compounds have been in- vestigated. Their synthesis is based on phosphonium and phosphino methanides: -Au Au - R2P-Au-PR2

R2P PR, R2P N Aii_'p Au—Pc ,P-Au-PR,

X R2P-Au-PR2

P-Au-PD

The structures have been determined by analytical and spectroscopic techniques, and, in some cases, by x-ray analysis. For a number of examples pharmacological properties have been found, which compare favourably with those of other compounds used previously in chryso-therapy. I

. f

152 III.a.25 THE RESOLUTION OF TRIS(HYDROXAMATO)11 AND TRIM iHIOHYDROXAMATO) COMPLEXES OF HIGH SPIN V/STRUCT /PLEXEi IRON(III) Kenneth N. Raymond and Kamal Abu-Dari A. DOJ Department of Chemistry, University of California, Berkeley, California 94720 USA *Depaj Madric **Chaj The siderophores (or siderochromes) are low-molecular weight compounds which are ring, manufactured by microbes to facilitate uptake of ferric ion. The insolubility of ferric hydroxide at physiological pH and the essential nature of iron for microbial tives, growth apparently engendered the production of this class of compounds by microbes. the re The fc Among the chelating functional groups found in the siderophores are hydroxamate, ne, si catecholate and thiohydroxamate. The preparation and properties of several complexes phtalj S OH (betwe n i the M. of the anion or dianion of thiobenzohydroxamic acid, 0-C-N-H, and benzohydroxamic phaniJ 0 OH SO amino » i ll I guencj acid, (|>-C-N-H, will be described. The neutral complexes, M((|>-C-N-H) and the salts M.O. I 3 r S 0 5re""lc l i sitioi K-[M(0-C=N;) ] (M = Cr, Co, Fe) have been isolated. The corresponding complexes tivelj 3 new cc 0 OH bearir for the parent hydroxamic acids, -C-N-H, have also been prepared for M = Cr, Fe. their The potassium salts have been prepared from the neutral complexes by dissolution in strong base. Precipitation of the anions with A or A tris(ethylenediamine)- cobalt(III) affords resolution of the anions with the precipitated anion having an absolute configuration opposite that of the cation. Neutralization of the precipitated salt with acid and extraction with chloroform gives solutions of the resolved, neutral complexes - even in the case of the high-spin ferric complex. III.a.26 153

V,STRUCTURE-ACTIVITY RELATIONSHIP FOR THE NEW ANTITUMOUR AGENTS (Pt2+COM- /PLEXES WITH SULPHONAMIDE DERIVATIVES).

A. Doadrio *, D. Craciunescu*, C. Ghirvu**. *Department of Inorganic Chemistry, Faculty of Pharmacy, University of Madrid, Madrid"3, Spain. **Chair of Physical Chemistry, Faculty of Chemistry & Chemical Enginee- ring, ""Institutul Politehnic lasi", Iassy, Romania.

We prepared and studied Pt(L)gX2 (where L=sulphaniamide deriva tives, X=C1", Br" , I"),complexes, as potential antitumour substances, Ey the reaction between, I<2PtX4 (X=C1~, Br", I") and sulphonamide derivatives. The following sulphonamides were employed: sulphanilamide, sulphamerazi- ne, sulphacetamide, sulphapyridine, sulphisoxazole, sulphametazine, and phtalylsulphathiazole. I.R. spectra of the new complexes were registered (between 4.000-250 cm-j in KBr pellets), and discussed in connection with the M.O. Huckel's calculations (performed on the ligands molecules). Su^L phanilamide and their derivatives are coordinated to Pt2+ through the — amino group of the benzene ring, and the displacement of the v-NH fre- quencies takes place towards lower values of the same order of magnitude. M^^^JLuckel' s diagrams indicated that the highest IT electr^n_ic_^harges - rare localize"d on the -NH2 groups of the ligands. On the basis" of the po- sitions and intensities of the vPt-Cl bands (337, 327 cm"1 and, respec- tively 325 cm'M we assigned different cis and trans structures for the new complexes. The antitumour action of the complexes (on the animals — bearing L 1210 and P 388 tumours) was also described in conection with - their cis structure. 154 III.a.27

I STEREOCHEMISTRY OF COBALT(II) CARBONIC ANHYDRASE AND INHIBITOR DERIVATIVES I. Bertini, C. Luchinat and A. Scozzafava Cattedra di Chimica Generale ed Inorganica dell'Istituto di Chimica Farmaceutica dell'Universita di Firenze,via 6. Capponi 7, Florence,Italy

Carbonic anhydrase is a metalloenzyme containing one mole of zinc(II) per mole of enzyme. The native zinc can be substituted by cobalt(II) with minor changes in the enaymatic activity. The knowledge of the stereochemistry of the enzyme as well as of the adducts with ligands which act as inhibitors is an important step in the investigation of the enzymatic activity. With this aim we have investigated electronic (7,000-25,000 cm"1) and C D (14,000-25,000 cm"1) spectra of several cobalt(II) carbonic anhydrase derivatives. Analysis of the near infrared spectra have been found particularly significant with respect to the assignment of the stereochemistry. We propose for the carboxylate(acetate, benzoate,oxalate etc) derivatives as well as the iodide and bromide derivatives a five coordinate structure, whereas sulfonamide, and aniline adducts are confirmed to be tetrahedraKI.Bertini,C.Luchinat and A.Scozzafava, J.Am.Chem.Soc. , in<>press). By comparison with the previous spectra, the stereochemistry of the forms of the pure enzyme has been suggested.

The coordination of bidentate ligands like anthranilate, oxalate and aminoacids deserves a further comment. The electronic spectra of these adducts indicate a monddentate behavior of these ligands towards the metal. However, the stability constants are larger than the corresponding monofunctional ligands, suggesting a further interaction of the second 13 uncoordiiiate group with the wall of the cavity. C nmr and T, .- -• •—g A. measurements on the acetate and oxalate adducts allowed to prove the existence and to locate a second binding site not involving the metal itself although very close to it (A.Lanir and G.Navon,Bi6ohim.Biophys. Acta, 341, 65(197"+)). III.b.24 155

\3 DYNAMIC STEREOCHEMISTRY OF CIS-OCTAHEDRALBIS(p-DIKETONATO) COMPLEXES. INDUCED OPT V Paolo Finocchiaro,Vito Librando.Pietro Maravigna and Antonino Recca Faculty of Engineering of the University, Viale A.Doria, 6 - 95125 Catania(Italy), Department Faculty of In continuation of our investigation dealing with the static and dynamic Department stereochemistry of propeller-like molecules we recently turned our attention Oasilla 233 to the stereochemical behaviour of some jS-diketonato complexes of the elements of the IV group and of transition metal elements,concentrating our attention on the dynamic behaviour of some representative bis-chelate molecules with the aid of permutational analysis and topological representations. and an bete In previous related studies,deal ing with the analysis of chemical isomers hibit indue and isomerizations in two-, three-, and four-bladed propellers, we established lla and S.I the relevance of permutationalanalysis and group theory in the description transfer tr of the stereochemical aspects of such systems. This approach, led inter alia tters IV t to the description of the concept of stereochemical correspondence which L or D-pr establish that two systems, no matter how chemically disparate, can be analyzed region of t in the same way granted that they possess the same point group symmetry (or ton Inorg. proper subgroup) and the same permutation group. The use of such an approach led us to enumerate the number of differentiate isomers for any substitution on chelatio pattern in these J5-diketonato complexes and to ascertain that the lowest energy the existen rearrangement mode (M.) occurring in such complexes and involving a reversal of the helicity of the structure, is permutationally equivalent to the "one- lar effect ring flip" mechanism of diaryl derivatives of the type ArgZX, which,in turn, and asparti are demonstrated to be stereochemically correspondent to these bis-chelate the metal i molecules. The activation energies, determined through line-shape analysis activity. of the experimental spectra, associated with such rearrangement mode^M. are in the range 16-18 kcal/mol for tin derivatives and only in the case of bis- mixed compl (acetylacetonato)bistriphenylphosphine ruthenium (II) such a barrier is suf- ne , where ficient high to allow resolution of the two enantiomers at ambient temperatu- or D-proli res. Thus, the latter compound can be regarded as an example of a two-bladed propeller molecule in which chirooptical properties can easily be investigated. throv ligtb some of th nitrogen d

156 III.b.25

ISOLATION AN] INDUCED OPTICAL ACTIVITY IIJ COMPLEXES OF Cu(Il) AND Zn(ll) WITH DIAMINE)COBA] ACIDS AND AKCKATIC BASES M. FOJita*, : # S.BUKSL , C, IBARRA , C.A. BUNTOK Department o Department of Inorganic and Analytical Chemistry *Departtnent i Faculty of Chemioal Sciences, University of Chile The column cl Department of Chemistry. University of California, Santa Barbara by Yoshikawa Caeilla 233 Santiago , Chile very useful : complexes su< The 1 : 1 J 1 mixed complexes of Cu(ll) with L or D-aminoacids methyl-1, 3-] i Kojima, H. Fi and an heterocyclic base such as 2,2 - dipyridyl or 1,10-phenanthroline ex- (1975) and tt hibit induced optical activity in the (d -*O( L.Gil , E.Moraga , H.Bo'badi- In the preser lla and S.Bunel J.inorg.nucl.Chem XL » 2509 » (1975) ) and in the charge [Co(NH3)2(tn) transfer transitions( S.Bunel , C.Ibarra and C.A.Bunton Inorg.Nucl.Chen,Le- be presented. tters 21 f 213 » (1575) )• Tiie corresponding mixed complexes of Cu(ll) with Work(J. Am. C L or D-proline show , for the first time , a Cotton effect in the absorption and Stranks(A region of the heterocyclic ligand ( S-.Bunel , C,Ibarra , A.Urbina and C.A.Bun- far been unsu ton Inorg.Mucl.Chem.Letters , in press ) . An aqueous so This fact could be due to the particular structure of proline since, poured on a c on chelation , generates a second asymmetric center at the N atom j whereas eluted by a 0 the existence of a ring in the molecule turns it into a rigid ligand, A siai- curve showed lar effect in 1 : 1 : 1 complexes of Cu(ll) , dipyridyl or phenanthroline corresponded and aspartic acid would indicate that the disposition of the rings around isomer, and t the metal ion plays a determining role in this type of induction of optical were assigned activity. electronic abi A related but somewhat different phenomenon is seen in 1 J 2 : 1 electn mixed complexes of Zn{H) , dipyridyl or phenanthroline and L or D-proli- circuli ne , where the sign of their rotation is opposite to that of the Zn-bia L The CD strengi or D-prolinates and their intensity markedly enhanced. observed by Fi The search of an explanation for the experimental evidence oould relationship * throw ligth on the general mechanism of induction of optical activity. and [Co(en)-]" complexes will some of these compounds, for istance CuPc, do not form adducts with nitrogen donor bases.

*••(., III.b.26 157

$/ ISOLATION AND CHARACTERIZATION OF OPTICAL ISOMERS OF CIS-DIAMMINEBIS(TRIMETHYLENE- DIAMINE)COBALT(III) CHLORIDE M. FOJita*, Y. Yoshikawa, H. Yamatera and K. Yamasaki Department of Chemistry, Faculty of Science, Nagoya University, Nagoya, 464 Japan *Department of Chemistry, Nagoya City University, Nagoya, 467 Japan 4 The column chromatography on SP-Sephadex which was first applied to metal complexes by Yoshikawa and Yamasaki(Inorg. Nucl. Chem. Lett.,4^, 697(1968)) has proved to be very useful in separating geometrical istmers and resolving optical isomers of cobalt complexes such as [Co(dien)2]Cl-(dien«diethylenetriamine), [Co(ibn),]Cl,(ibn*2- methyl-1, 3-propanediamine), [Co(linpen)]Cl_(linpen»linear pentaethylenehexamine) (M. Kojima, H. Funaki, Y. Yoshikawa, and K. Yamasaki, Bull. Chem. Soc. Jpn., 4jJ, 2801 (1975) and the references cited therein). In the present report isolation and characterization of optical isomers of cis-

[Co(NH_)2(tn)2]Cl,(tn=trimethylenediamine=l,3-propanediamine) by this technique will be presented. The trans-isomer of this complex was first prepared by Bailar and Work(J. Am. Chem. Soc.,^, 232(1946)), and later characterized by Jonasson, Lincoln and Stranks(Aust. J. Chem. ,£3, 2267(1970)), but isolation of the cis-isomer has so far been unsuccessful. An aqueous solution of this complex prepared by the method of Bailar and Work was poured on a column of SP-Sephadex(^ 2.7 x 135 cm), and the adsorbed complex was

eluted by a 0.15M solution of sodium (+)coo-tartratoantimonate(III). The elution joy curve showed a large peak with two shoulders on the tail side. The main peak 3+

corresponded to the A -cis-[Co(NH.)2(tn)2] ion, the first shoulder to the A-cis- isomer, and the second shoulder to the trans-isomer. These absolute configurations were assigned on the basis of circular dichroism(CD) and C-13 NMR spectra. The electronic absorption and CD spectra had following peaks for the A —isomer. electronic absorption: 486 nm(logg- 1.82), 347 nm(log£ -1.90) , circular dichroism: 534 nm( A£ - +0.014), 475 nm( &£ - -0.041). f+ 3+ ion is about 1/4 of that of [Co(tn)»] ion observed by Fujita, Yoshikawa and Yamatera(Chem. Commun.,941, 1975). A similar 3+ relationship was observed for the ethylenediamine complexes, [Co(NH,),,(en) ] 3+ 0 and [Co(en),] ions, too. Other properties of these diamminebis(trimethylenediamine) complexes will alro be reported. will be discu hemocyanin i

158 III.b.27

7 ISOLATION Al A. Takeuchi STEREOCHEMISTRY AND REACTIVITY OF SOME OPTICALLY ACTIVE Institute o: COMPLEXES OF CO(III) • Toyonaka, Oi M. M. Muir and J. A. Diaz The present Department of Chemistry University of Puerto Rico pairs of is< Rio Piedras, Puerto Rico 00931 U.S.A. copper(II), Optically active dichloro-, chloroaquo-, and diaquotetramine cobalt(III) Cu(X-sal-ch; complexes have been prepared and characterized. The tetramines used able only ii are C-methyl substituted derivatives of triethylenetetramine (trien). The rates and activation parameters for the hydrolysis reactions of the planar mole< dichloro complexes have been measured. In general, the complexes the same cor aquate to the corresponding chloroaquo ions with retention of configur- ation and optical activity. The trans isomers, however, normally aquate the complex to the cis-8 -chloroaquo or diaquo ions, with retention of configuration. form at 105- Of special interest are the results obtained for the trans-SS-CCo(2S,5R,9S- MegtrienK^J + ion, an unusually stable trans isomer of a cobalt(III) form is trai trien complex. This hydrolysis to the diaquo complex is accompanied by studies, the a change of configuration. is not coplc Amino acid and peptide derivatives of the optically active series of dihedral anc complexes have also been prepared and characterized to examine steric 47.4°. This effects in a system with a metal ion and two different ligands of known geometry. sal-i-pr)2, form (monocJ angle of 57.

sal-i-pr)2' chemistry tc form at 102* Bis(N-cyclol which were j form, the Ci temperature green and bi were also ol brown chlorc crystals. I Spectral anc ed in relati (II) complej me eiecirocnemicai reaox properties oi i ana c wiU be discussed in reference to oxygen reactions of the copper containing proteins hemocyanin and tyrosinase.

III.b.28 159

ISOLATION AND PROPERTIES OF ISOMERS OF BIS(SALICYLALDIMATO)COPPER(II) APPI A. Takeuchi and S. Yamada Institute of Chemistry, College of General Education, Osaka University Toyonaka, Osaka 560, Japan The present paper describes isolation and characterization of several Depa pairs of isomers of bis(N-isopropyl-ring-substituted salicylaldiminato)- Partia copper(II), abbreviated as Cu(X-sal-i-pr),» and the cyclohexyl analogues, aqueous s Cu(X-sal-ch)2' It has been believed that Cu(3-CH3O-sal-i-pr)2 is obtain- Figure able only in olive-green crystals, which were concluded to consist of when A-[C planar molecules. We have now succeeded in obtaining brown crystals of enriched the same complex by evaporating a solution of the brown crude product of the absol 0 the complex at 30 . The brown form is also obtained by heating the green [Co(acac) form at 105-110° for a few hours. With the rise of temperature the green and A ena form is transformed at 101° into the brown form. According to X-ray optically studies, the Cu(N)2(O)>i group in the olive-green crystal (orthorhombic) oxidized is not coplanar but distorted markedly from the planar structure, the The optic dihedral angle between the CuNO planes in the molecule being as large as amount of 47.4 . This is in contrast with the low temperature form of Ni(3-CH O- 3 purity of sal-i-pr) , which was concluded to be planar. The brown high temperature 2 in the el form (monoclinic) has a distorted tetrahedral structure with the dihedral Q A- and angle of 57.9 . A similar pair of isomers was isolated for Cu(5,6-benzo- In this c sal-i-pr)2. Its olive-green form, which probably has a similar stereo- oxidation chemistry to that of Cu(3-CH3O-sal-i-pr)2# is transformed into the brown form at 102°. Bis(N-cyclohexyl-salicylaldiminato)copper(II) was isolated in two forms, which were purified b£ recrystallization. In the brown low temperature form, the Cu(N)2(O)2 group is perfectly planar. The olive-green high temperature form may probably have a tetrahedral structure. The olive- green and brown isomers of Cu(5-Br-sal-ch), and Cu(5,6-benzo-sal-ch)0 were also obtained. The olive-green compound Cu(3-CH3O-sal-ch)2 and its brown chloroform adduct Cu(3-CH3O-sal-ch)2.2CHC13 were isolated in crystals. Possible structures of these compounds are discussed. Spectral and other properties of these isomers are presented and discusfl- ed in relation to their structures. The results for the copper- (II) complexes are also compared with those for the nickel(II) complexes. Fig.l. A] of partie 160 III.b.29

APPLICATION OF THE PFEIPPER EFFECT TO PARTIAL RESOLUTION OF LINKAGE TRIS(ACETYLACETONATO)COBALT(III) RUTHENI Hayami Yoneda and Katsuhiko Miyoshi H.-J. S Department of Chemistry, Hiroshima University, Japan Institu Olshaus Partial resolution of [Co(acac)3] was performed by oxidation of an aqueous solution of racemic Li[Co(acac)3J with A- or A-[Co(phen)-JC1-. Since t Figure 1 shows tha- AB and CD spectra of organic phase obtained (TBA+ = when A-[Co(phen)3]Cl3 was used as a chiral environment compound. The SCN" gr enriched enantiomer of [Co(acac)3] produced in the Pfeiffer system has a "hard the absolute configuration of A. When A-[Co(phen) ]C1 was used, A- 3 3 (H.H. S [Co(acac) ] was enriched. This means that the equilibrium between A 3 R.A. 3a and A enantiomers of [Co

of partially resolved A-[Co(acac)3]. III.b.30 161

LINKAGE-ISOMEkIC HEXAKIS(THIOCYANATO-ISOTHIOCYANATO)COMPLEXES OF ENERGY LE RUTHENIUM(III) AND OSMIUM(III) S.Bunel, H H.-J. Schwerdtfeger and W. Preetz Institut fiir Anorganische Chemie der Universitat Kiel Department Faculty of Olshausenstr. 40-60, D-23OO Kiel, Germany University

Since the first preparation of (TBA)r,[Ru(NCS)<-] and (TBA)o[0s(NCS)cj Crystal fi (TBA = tetrabutylammonium) it was doubtful whether the ambident carried ov SCN~ group is bonded as a "soft" ligand via S (thiocyanato) or as a "hard" ligand via N (isothiocyanato) to the trivalent central ion The field (H.H. Schmidtke and D. Garthoff, Helv.Chim.Acta, J50 1631 (1967), simmetry i R.A. Bailey, S.L. Kozak, T.W. Michelsen and W.N. Mills, Coord. Soc.(A), 2 Chem.Rev. 6, 407 (1971)). iR-spectra are comgAtible with both possibilities, and exchange reactions with SVCJN" yield evidence The crysta supporting both N- and S-bonded groups (S.Wajda and K.Rachlewicz, and C were Nukleonika jj_8, 407 (1973)). Using high voltage electrophoresis £co (ox)3 ] (V. Preetz, Fortschi .Chem.Forsch. V\.' 375 (1969) we have now been namurty ar able to show unequivocally that both substances are actually mix- tures consisting of at least four ore three linkage isomers of the The calcu] type spectra ai (TBA)3[Ru(NCS)n(SCN)6_n], n = 1, 2> 3, 4, and and T.S. I

(TBA)3[Os(NCS)n(SCN)6_n], n = 2, 3, 4. ation of 1 Since the rate of migration of the complex anions in an electric field increases stepwise by 5-10% with increasing n, sharply separated zones of different colors are obtained. After elution the stable TBA salts are precipitated. They give distictly different UV, VIS, IR and Raman spectra, but identical analyses. They are the first linkage isomers to be isolated which have exclusively N- or S-bonded SCN ligands (R.J. Balahura and N.A. Lewis, Coord. Chem.Rev. £0, 109 (1976). Equilibration between several hexakis (thiocyanato-isothiocyanato)complexes shows that Ru and Os are borderline cases between hard and soft acids. The kind of bonding of the ligands is therefore largely adopted at random. The vibrational spectra are discussed. or trie been s

162 III.b.31

ENERGY LEVELS AND OPTICAL ACTIVITY OF TRIS G< -AMINOACIDATES OF COBALT PECTROSC S.Bunel, H. Del Canto RH0DIIM( I Department of Inorganic and Analytical Chemistry CONTAINIK Faculty of Chemical Sciences, University of Chile - Casilla 233,Santiago, CHILE. C.Preti, Istituto Crystal field calculations for triscK-aminoacidates of Co(III) are 41100 Mod carried out, via the strong field formalism. In vi

The field produced by the ligands is treated under C2 and C, micro- we have 'b simmetry for the trans and cis isomers. (E.Larsen and S.F.Mason J.Chem. tie. This Soc.(A), 313, (1966) ). and is ve Furthermo The crystal field parameter/P^N and-(^Sand the repulsion parameters B ant if ogga: and C were obtained from the parent complexes: I Co(en),| and I -3 LCo(ox), I and corrected for different distortion angles. (R.Krisch- The b namurty and W.B. Schaap J.Chem. Ed, 47 , 433 , (1970) ).

The calculated ,energy levels, are compared with the visible absorption spectra and with the circular dichroism spectra in solution (R.G- Dening forms int and T.S. Piper Inorg Chem. , 5 , 1056 , (1966) ) and a new interpret- coordinat ation of the optical activity of this kind of complexes is proposed. le ring o complexes dium(II) i.r. stud and magne diamagnet te of the racterize* takedral : represent! tidum der: of these cores to be assigned. Several of the products have been structurally characterized by X-ray analyses.

III.b.32 163

3PECTR0SC0PIC INVESTIGATION ON THE STRUCTURE AND STEREOCHEMISTRY OP NEW. VpSEUDOTETRA RHODIUM(III),' IRIDIUM(III), PALLADIUM(II) AND PLATINUM(II) COMPLEXES G.Marcotrig CONTAINING BENZOXAZOLE-2-THIONE AS LIGAND *Istituto di C.Preti, G.Tosi and P.Zannini 70126 Bari. Modena, 411 Istituto di Chimica Generale ed Inorganica, University of Modena, 41100 Modena (Italy). 3ft piperazine, In view of the importance of the oxazole group in biological systems, pared and i the complex we have begun a study of the coordination behaviour of benzoxazole— 2-thio 4.72 B.M.), ne. This molecule has a marked bacteriostatic and fungicidal activity Co(II) m s Chem., 5^31 and is very important as plant regulator on plant growth and development. gnetism sme Furthermore this heterocyclic base is very important as a stabilizing or J.Amer.Chen gy bands, £ antifoggant agent in photographic emulsion adsorbed on bromide. ted and ass The benzoxazole-2-thione P) (6000-8C the d-d bar probably ai potential, trigonal dJ and the li< forms interesting complexes with transition metal ions being potentially Soc, 92., 4* coordinated through either the nitrogen or the oxygen atom of the oxazo- nds: pipers from the e: le ring or via the sulphur atom. We report here an investigation of the ased by tin complexes formed by this ligand with rhodium(HI), iridium(lll), palla- than a met! dium(II) and platinum(II). The nature of bonding has been ascertained by basis of a i.r. studies (4000-50 cm ) and electronic spectra, conductivity data that spin-< and magnetic susceptibility measurements. The complexes resulted always the splitt: and conduc diamagnetic N-bonded, with the ligand acting as monodentate only, in spi- significan te of the presence of three potential donor atoms. The complexes were cha bands at 3 2750-00 cm' ratrterized as covalentj all the rhodium and iridium complexes have an oc- as the hal 2 3 drogen ban' tahedral structure d sp with mer-configurations (Cp symmetry), 2a1+b1 crystallin representations for the MX3 and MN3 stretchings. The palladium and pla- nable cerct; 2 halogen va: tiatun derivatives have a cis square planar dsp structure. be^ equal t> assignment 1-CH3pip2 i other pseu three theo. which coi in chryst

164 ; ,^>r]K III. b. 33

VpSEUDOTETRAHEDRAL COBALT(II) &NITTERION COMPLEXES. t'ÊTÜDIES OK K G.Marcotrigiano*, L.Menabue** and G.C.Pellacani** 'DERIVATIVES ^Istituto di Chimica, Pacoltà di Medicina-Veterinaria, University of Ban, Jo de O. Ca 7 0126 Bari. **Istituto di Chimica Generale ed Inorganica, University of Laboratório Modena, 41100 Modena. Italy. Porto,Portug

JoX3(L^) (X=Cl,Br,I) and CoX8Y(Lft) (X=Cl,BrjY=Br,I?X^Y;Lj=monoprotoiiated piperazine,1-methylpiperazine and 2-methylpiperazine) complexes were pre- Although pared and investigated. The symmetry of the metal-ligand environment of dine and it the complexes is approximately C3V or Cs. The observed magnetisms (4•31 — zed,the coo: 4.72 B.M.), which vary in the sequence Cl*~E(Tif 1 ?) (6000-8000 cm" ) transitions, respectively, in the C3V symmetry, while to prepare i 1 the d-d band appearing at 13500-17500 cm" is a multicomponent absorption, and 2-,3-,ai probably arising as a result of both spin-orbit coupling and the trigonal 1 are new,witl potential. The splitting of the A2 and E bands (240-300 cm" ) measures the trigonal distortion and the difference in Dq values between the halide X Most of 1 and the ligand L (B.B.Garrett, V.L.Goedken and J.V.Quagliano, J.Amer.Chem. Soc, £2,489(1970)) and gives a spectrochemical order of the cation-liga 2"4 nds: piperazine<2-methylpiperazine<1-methylpiperazine, which may be caused 3-iodopyridj from the effect of the positive charge on the cation-ligand greatly incre- ted by magnt ased by the presence of a methyl group directly on the charged nitrogen pseudo-tetrj than a methyl group in the orto-position. The electronic spectra of the halogen brie CoX2Y(LjJ), identical to those of the CoX3(Ljij), are also assigned on the basis of a C3v symmetry,instead of an expected Cs symmetry, confirming Among the that spin-orbit coupling effects are the principal factor responsible for ligand,we we the splitting of the T bands, prevailing on the geometry effects. Spectra of the pyric and conductivities (30-80 S»cms.mol"1 at 25°C) in BMP (10"3M) suggest a significant amount of dissociation. The i.r. spectra of the complexes show obtained a c bands at 3150-60,4 3050 cnr£ (\>(NH) of the coordinated nitrogen) and at prising sine 1 2750-00 cm" (v(NH2) or v(WHCH3)). The stationariety of the latter bands,• four molecul as the halide changes, suggests that these groups are not involved in hy- drogen bonding and that the awitterion complexes have a highly ordered Our resul crystalline structure. Assignements of the v(Co-X) are made with a reaso«- unable to cc nable certainty, being available several sets of compounds in which the Houk and K. halogen vary from Cl to Br to I. The number of experimental bands found to be. equal 'to the theoretical bands also supports the assignment. Tentative [CoCl2(2-0Hp assignment of the v(Co-N) vibration (232-222 in the pipz, 264-255 in tha which Bsens 1 1-CH3pipz and 284-270 cm" in the 2-CH3pipz) are made by comparison witlt Further wo other pseudotetrahedral Co(II) complexes. Por the CoX (LjjJ) complexes the 3 The autho three theoretically prevedible bending modes are also assigned. Portugal) f o a uuuuer ox cxeunpxfc \> pnarmacoiogicai properties xictve u*s*su which compare favourably with those of other compounds used previously in chryso-therapy.

L III,b.34 ' , 165

^STUDIES OH MOLECULAR COMPLEXES OF COBALT(ll) AND NICKEL(ll) WITH SOME PYRIDINE COBALT CC '' DERIVATIVES V J. de 0. Cabral.M. F. Cabral and M. T. P. Leite A. Monac. Laboratorio Ferreira da Silva Paculdade de Cieneias Laboratoi Porto,Portugal Spettrocl Consiglic Although a great number of mixed complexes of transition metal ions with pyri- We have 1 dine and its derivatives,as molecular ligande,have been prepared and characteri- dithiocai zed, the coordinating properties of pyridine derivatives is still a matter of In many i great interest. differeni We have been centering our attention on halo-,hydroxy-,and carboxylpyridines. G.Mattogi Complexes with 2-,3-,and 4-chloro and bromopyridine,as well as with 3- and 4- Inorg.Nuc -benz oylpyri dine, have already been studie

unable to confirm the synthesis of fcoCl2(2-0Hpy)5J and [boCl2(2-0Hpy)J (C.C. Houk and K. Emerson,J.inorg.nucl.Chem.,2P_,1493(l968)),since we always obtained

[CoCl2(2-OHpy) jj ,but we prepared a compound with the composition CoBr2(2-0Hpy),, which seems to be pentacoordinate. Further work on these and similar complexes is,at present,being carried out. The authors thank the Instituto Nacional de InvestigagSo Cientffica (Lisboa, Portugal) for financial support. r,' -. 166 III.b.35 c COBALT COMPLEXES CF METHYL ESTERS OF DITHIOCARBAZIC ACIDS i'i A. Monaci and F. Tarli SYNTHES: Laboratories di Teoria e Struttura Elettronica e Comportamento Spettrochimico dei Compost! di Coordinazione I, B .Bart Consiglio Nazionale delle Ricerche - ROMA (Italia) G.G.Sad: We have been interested for some time in the ligand behaviour of N.S.Kuri dithiocarbazic acid NH?NHCS?H and its N and S substituted derivatives. In many reactions with transition metal salts these ligands have shown It is ii different behaviour depending on the type of substitution (C.Battistoni, carboxy] G.Mattogno,A.Monaci and F.Tarli, J. inorg.nucl .Chem. ,_3£, 3815 (1971); thioacel Inorg.Nuel.Chem. Letters, 7_»981,1081(1971)). We have undertaken a study and al. of the complexes of tfH^HCSjCHg (I) with cobalt with the aim of correlating the oxidation state of cobalt with the electronic struture with RhJ of the ligand. I car. coordinate in neutral form (NH2NHC(S)SCH3= LH) or [Rh2(C6I in anionic form (NH NC(S)SCH, = L). In anhydrous conditions I reacts specera in form LH giving the pseudo-tetrahedral complex Co(II)(LH)«C1_,whereas tfalobeu: in aqueous media it reacts in both forms LH and L giving successively in the t

Co(III) (LH)2LCl2->> Co(III)(LH)L2Cl2->Co(III)L3. In acid media, and depend c in a N_ atmosphere, the pseudo-octahedral complex Co(II)(LH)-Cl2 is of the £ obtained which is oxidized by 02 (even in the solid state) to Bj

Co(III)(LH)2LC12. The importance of form L in the stabilization of action i Co(III) complexes was confirmed by the fact that CoCl_ reacts with lised bj

NH2N(CHg)CS2CH3, which cannot give the form L, leading in every case in thioi to pseudo-tetrahedral Co(II) !"NHON(CH,)CS.CH-1O C1_. in the e

X-ray structural data for Co(III)L2LHCl«H20 do not show significant = 2,10 5 differences between LH and L. We are developing the present work in order to obtain quasi-planar Co(II) complexes employing new ligands complex derived from the condensation of I with suitable dicarbonyl compounds. have bee III.b.36 167

SYNTHESIS AND INVESTIGATION OF THIO- AMD DITHIOCARBOXYLATO COMPLEXES OF RHODIUM I.B^Baranovskii. M.A.Golubnichaya, L.M.Dikareva, Ya.V.Salyn, G.Ya.Mazo, G.G.Sadikov and R.N.Stcholokov N.S*Kurnakov institute of general and inorganic chemistry, Moscow, USSR It is interesting to compare the properties of some carboxylato, thio- carboxylato and dithiocarboxylato complexes of Rh(II). Recently some thioacetic complexes of rhodium(II) have been obtained (I.B.Baranovskii and al. Zh.Neorgan.Khim. £1, 1085 (1976)). [Rh(CgH,-C0S)4(CgHcCS0H)2"] was obtained by reaction of thiobenzoic acid with Rh2(R000).. Also we have prepared diamagnetic dimeric compounds [RhgiCgHcCOSJ.LgiCL = Py, Thio, DMFA, DMSO and ext.). IR and ESCA spectra of thase complexes have been investigated. Axial ligande in thiobenzoato complexes Rh(II) with rhodium atoms are bonded weaker than in the same thioacetato complexes. The Rh 3dc/2 binding energies don't depend on the nature of the substitutes (H, CH,, CgHg) and the nature of the axial ligands. Binuclear thiocarboxylato-bridged structure and metal-metal inter- action for [Rh2(CH3C0S)4(CH.jCS0H)2] (Rh-Rh = 2,550 2) have been estab- lised by X-ray diffraction study. Axial S-bonded CH-CSOH molecules are in thion form. The two sulfur atoms as well as the two oxygen atoms in the equatorial plane are mutually cis (Rh-S = 2,260 2; Rh-0 (average = 2,10 £). Dithioacetic acid reacts with carboxylates of Rh(II) to yield complex Rh(III) - [Rh(CH3CS2)3]. This complex and JRh(CH3CS2)2Cl2"}~ # have been prepared by reaction of RhCl, 3H20 with CH-CSgH. III.b.37

OW A,.V t», Syamal anu V.jJ.ühaneicar ^apartment of Applied Sciences and humanities, B.N.Chakravarty University, ioiruKShetra-132119, Haryana, India ifew cobaltUH) he te roche late s oi' the type [Co(AA>)( s albn)J (where kk. a oidentate monobasic ligands LUe picolinic acid, acetylacetone, tropolona, if-benzoylphenylhyaroxylamine , acetoaceCaniliae, salicylaldehyde, 2- hydroxy-1-naphthaläehyde; salbnHa= W,N'-ethylenebis(salicylideneimine)) have been synthesized ana characterized by conductance, infrared and electronic spectra, molecular weight anci magnetic susceptibility measurements. The quadriaentata Schifi base salbn is coordinated to cobalt(III) in a non-planar twisted configuration anc the bidentate ligand adopts two cis positions. The heterochelates have a distorted octahedral structure. The compLexes are diamagnetic and non-electrolytes in methanol. Molecular waight measurements indicate the monomeric nature oi' the complexes, l'he complexes exhibit two ligand field bands at around 16000 ana 24") DO cm aue to the transitions 1JL, ^—A ^T-,- 1 - - lg ' xg respectively, i'he electronic spectra of [Co(AL)(salbn)J in non-coordinating and coordinating solvents are very similar indicating the stable nature oi' the heterochelates in pyridine. The phenomenon of ehelate ring effect has been used to explain the stability of the conplexes in pyriaine. ' - 1.- 1 /• " L • I III.b.R.3 c 169

Formation of tetrameric Co(ll) fluoro clusters from Co(ll) tetrafluoroborates and N-alkyl imidazoles TIG* OP COPP] J. Reedi.jk, F.B. Hulsbergen, P.J. van der Put and J.A. Welleman Shahic Department of Chemistry, Delft University of Technology, Delft-2208, The Netherlands Indusi Dean'j Decomposition reactions of metal tetrafluoroborates upon reaction with strongly IIT, coordinating ligands have been reported recently. The present gravimetric In most cases metal fluorides MFO or adducts MF0(ligand)2 precipitate (e.g. M.A. Guichelaar et.al., Inorg. Nuol. Chem. Letters J£, 999 (197*0). Very recently it formation. has been found that products containing both fluoride and BFJ" ions may precipitate 10 IU g/nl anc (C.G. van Kralingen and J. Beedijk, J. Chem. Soa. Chem. Commun. 1976, 533). In this ing several 2+ case a dimeric species COgFp(ligand)g with BF. counter ions was formed. However, with a water also monomeric species like Mo(HpHp)F(dpe)p and BFJ* have been reported recently each of 1,1C (M. Hidai et.al., Inorg. Chem. J£, 269b (1976)). acid (S). 2 We now wish to report a species M(ligand),F(BF^), which is formed for the ligand bath for SO /V-ethyl imidazole (M = Cc, Mn, Cd) and iV-propyl imidazole (M = Co only). The products is then filt precipitate from solutions of the metal(ll) tetraf luoroborates in ethanol upon which factor 0.166 the ligand is added in a ratio 1:U. complex cont All formed products are powder isomorphous and have identical IR spectra. Ligand- for tne det< field spectra indicate octahedral coordination of the Co(ll) ion. Infrared spectra (50 ppm), iit 2+ indicate the presence of uncoordinated Brj" ions, and coordinated F~ ions (far-IR). Sr (100 pi Conductivity studies in acetonitrile and DMF agree with a tetrameric species SO" (500 ppn iv. Magnetic susceptibility fact that ft and saturation studies show "an ahtiferro^ acid or suli magnetic exchange between the metal ions by solvent (M = Co, Mn) of the order of a few cm • method thus Combining all available data, a cubane- type cluster seems most probable, and agrees with all measurements. A crystal- structure determination (M = Co) has started recently.

2+ • = Co O = 170 , <~*rr^ iv. 1 /4fiiiLYTlCid, APPLlCATIOHS OF UlXHi) LIGAUD LGkBLUXES-1. SEPARATION-DBTJSKMISA- TIC* OP COPPER(II) AS IIS COMPLEX WITH 1,10-PRbJSAKTHROLINE AND SALICYLIC MOD. Shahid Abbas Abbasi ." / S.G.Goncal-v Industrial Research and Consultancy Center Department Dean's Office XIT, Powai, Bomb ay-76, BUI A -iua liarquea The present method is one of tue very few reported separation- The raethod gravimetric determination methods based on nixed ligand complex yielding a 2+ format!on, Traces ol copper when present in concentrations The rcaximun; lOiug/Kl and above, can be separated from aqueous solutions contain- ing several other anions and cations by precipitating it at pH - 4 beins the c with a water-ethanol solution(5 /. etaanol) having 1.0 x 10 M of acid is 0.0 each of 1,10-phenanthroline (P) and monosodium salt of fealicylic Titanium, v acid (S). The precipitate and mother liquor are digested on water must be sep bath for SO minutes and cooled to room temperature. The precipitate The separa is then filtered on glazed silica, dried at 3b°C and weighed(conversion relations a, factor 0.1664). It is shown that the precipitate is a mixed ligand .2+ complex containing Cu P and S in a ratio 1:1:1. Tolerance limits 2+ 2+ 2+ for tne determination ( pp, for tne determination of 10 u g/ml of Cu are Ni (50 ppm), Co (50 ppm), Mn2+ (50 ppm), (75 ppm), Ca2+(100 ppm), Ba2+(100 ppm), 2+ (5 pp, p 2 2 (100 ppffi), Ha1* (50 1 Sr2+ (100 ppffi), Ha1* (500 ppm), K1+ (500 ppm), Cl" (500 ppm), SOT (500 ppm), NO" (200 ppm). The merit of the method lies in the fact that the precipitate can be dissolved in 0.01 M hydrochloric acid or sulfuric acid and iron the solution P and S can be recovered by solvent extraction with n-butanol and can be used again. The method thus holds promise for lar^e-scale separations of copper. IV. 2 171

S' i -•• I -rZJA.'ClHCïü^T.HC; DJi'l-L Ii^riCNC? I'UING-JT:]!; -.VITE 3ALICYLIC ACID OLATILE CHEL • i S.O.Gonçalves and i:..u SG Galles .Andrads Louis G. Jamt i)e?art.v.3nt of Chemistry Pontiffcia Universidade Católica Department of J.ua. : .arqués de Cao Vicente,209 - ïio de Janeiro, Brasil Boulder, Cole -he laethod conpriaec tho co^ploxation of tungsten with salicylic acid Metal ß-diket yielding a reddish colour. volatility of and atomic at The .T.aximtur. absorbanc? of tho co.v.plsx lies within 410-420 nm, 420 nm organic solv shift reagent being the chosen wavelength. Tho final concentration of the salicylic illustratedCE acid is 0.0S0 ~/nl and the sensitivity is 0.13 ug V (/T)"1^"1. solutions wer : spectrophoton Titanium, vanadiun, rhcniu;n, and molybdenum interferes and of 30-fold wa synthes iy.ed—6 must be separated, titanium, beim; the strongest interfcrent. sufficiently atures. Conse The separation procedures, advantages of the method, stoichionetric lyzed by gas relations and equilibria;.: constants are discussed. mass spectroir being readily demonstrated response and compounds sue measurements into an acetv Complex

Mo02(tfa)2

Mo02(fod)2

Ho02(TTA)2

Ho02(tfafa]

Mo02(tfapa! M0O2(facam;

Mo02(thd)2 In the mass t observes the loss of CF3, CF2 (C.Reiche) (1967)). A no\ R-Ï-F from tl of metastable CF3 (except ii to be depend« not observed : the spectra oi 172 IV.3 / &ASCHROMA' VOLATILE CHELATES OF MOLYBDENUM

Louis G. Jambor and Robert E. Sievers J.Rudolpl Department of Chemistry, University of Colorado Pachberi Boulder, Colorado 803 09, USA There is an Metal g-diketonates have many important analytical applications.The volatility of these compounds is important in both gas chromatography suitable fc and atomic absorption spectrometry. The high solubility of chelates in elements. £ organic solvents makes them important in solvent extraction and as NMR shift reagents. A novel utilization of volatile complexes has been interesting illustrated(Hildesbrand and Piekett, Anal.Chem.,4 7, 4 24(1975)) where An analytic solutions were injected directly into the flame of an atomic absorption spectrophotometer via a heated injection port. A sensitivity increase elements is of 30-fold was achieved by this method for chromium chelates. Jfe_ha_ye formation c avn^hes^zed—several new molybdenum(V) and (VI) 8-diketonates, which are sufficiently volatile to be sublimed in vacuo at relatively low temper- the separat atures. Consequently these complexes exhibit the potential to be ana- optimizatic lyzed by gas chromatographic techniques, by atomic absorption or by mass spectrometry. These complexes hold the additional advantage of Volatile ch being readily formed and easily extracted into organic solvents. We have Sb, Cd, In, demonstrated that the volatile molybdenum chelates produce greater response and can be detected with greater sensitivity than non-volatile formation v( compounds such as ammonium phosphomolybdate when atomic absorption tions are measurements are made using the usual method of solution aspiration into an acetvlane-nitrous oxide flame, and using are separai Complex R1-C-CH=C-R2 Sublimation Temp, at 0.05 mm Hg 70°C The resv Mo02(tfa)2 CF3 CH3 oxides are Mo02(fod)2 C3F7 t-butyl 60°C temperature Ho02(TTA)2 CF3 thienyl 150°C chromatogrj Ho02(tfafa)2 CF3 furyl dynamic val Mo02(tfapa)2 CF3 phenyl 110°C

Mo02(facam)2 CF3 camphorate 160°C

Mo02(thd)2 t-butyl t-butyl 110°C

In the mass spectra the fluorinated molybdenum 8-diketonates, one observes the expected fragmentations of the molecular ion such as loss of CF3, loss of R-C, loss of ligand, and loss of ligand and CF2 (C.Reichert, J.B. Westmore, and D.H. Gesser, Chem.Commun., 782 (1967)). A novel rearrangement observed is the loss of R-C-F from the molecular ion and this is confirmed by the presence of metastable peaks. The fragment produced also exhibits loss of CF3 (except in the case of Mo02'fod)2)- This rearrangement appears to be dependent upon the presence of the; Mo022+ species, as it is not observed in the mass spectra of other metal B-diketonates or in the spectra of the ligands from which the metal chela.tes are formed. Fig.l. AE of partia

IV.4 173 xy £7 GASCHROMATOGRAPHIC SEPARATION OF INORGANIC COMPOUNDS USING 'CSV. OF TETRACY •?/ COMPLEX FORMATION I'.J.C.^astasi. J.Rudolph.K.Bachmann ,A.Steffen,S.Tsalas Department of Fachbereich fttr Anorganische Chemie und Kernchemie der P.O.Sox 11049, Tecnnischen Hochschule Darmstadt Application of There is an increasing demand for separation methods which are and actinide e suitable for the analysis of extreme low concentrations of trace elements. Separations which are carried out in the gas phase are Separation bet interesting due to the low contamination of the reacting gases. of benzyl alec An analytical system which allows the separation of most of the this last case elements is only possible at temperatures hiah enough for the formation of volatile compounds of many elements. Therefore all/' and th the separations are carried out as adsorption chromatography. An solution using optimization is achieved bv complex formation with suitable salts. . Volatile chlorides of Nb, Zr, Mo, Te, Tc, j)' Sn, Po, Pa, Bi,JJy Sb, Cd, In, As, Br, Hf, ^e, Ga, Os, Ru are separated by complex Hydrogen ion formation with NaCl, KC1, CsCl, BaClo, MgCl- and YC1,. The seoara- of lanthanide tions are carried out isothermatically at different temperatures alcohol-tetra< and using a temperature programme. In addition the same compounds are separated in a temperature gradient. The extractioi The results of the separations of volatile bromides and volatile except for uri oxides are presented also. The retention volumes, the retention was applied, i temperatures and the characteristic temperatures of the thermo- chromatography are discussed as mathematical functions of thermo- dynamic values. Pig.l. AB(—) and CD(—, •••) spectra

of partially resolved A-[Co(acac)3].

174 IV.5 L, ,- •JSn OF TETRAGYai.X AS COMPLLKI.sG AGE-IT HI ANALYTICAL CLE11ISTRY. AHALYTK

I'.J.C.Jastasj. \'.Saiki and F.W.Lima. K.M.Mohan; department of ."adiochemistry, Instituto de Energia Atoinica Departmeir P.O.Sox 11049, (Sao Paulo), (01000),(Jrasil) 492-002 (i Application of tetracycline as completing agent for the extraction of lanthanide and actinide elements has been studied. 3DTA having

Separation between uranium and was achieved by extraction with a solution part I,Vol. of benzyl alcohol-tetracycline, as well as separation of rare earth elements. In this worle i this last case counter-current procedure was applied. tines of r<

Uranium and thorium were separated by extraction with benzyl alcohol-tetracycline author* pr< solution using dietilenetriaminepentaacetic acid (DTPA) as masking agent for it was proi thorium. determinat: Hydrogen ion dependence and extractant concentration dependence of the extraction based on tl of lanthanide elements, , uranium and thorium into a solution of benzyl subsequent alcohol-tetracycline have been determined. EDTA In The extraction experiments vrere carried out using radioisotopes of each element, proportions except for uranium in which case activation analysis with epithermal neutrons was furthe was applied. Measurements were uade by means of gazxsa-ray spectrometry. formaldehye the rapid *ere derel< under the chromiua(i: in a in nitrate law orer a colour is s derelopod 1 IV . 6 175 ANALYTICAL APPLICATIONS OF CHROMIUM llll] - EDTA COLOUR SYSTEM 7 K.M.Mohana Rao and K.Satyanarayana Department of Chemistry, Sovernment College of Science ,Ralpur, 492-002 (M.P) INDIA Chromium(III) was reported to develop a violet complex with 3DTA having an absorption peak: at 538nm(Treatise on Analytical Chemistry, part I,Vol.2,Kolthoff and Elving,p,904(1961). Literature indicated that this worte was never completed; investigation of reactant concentrations, times of reactions, interference effects,etc.» remains to be done. The authors proposed to re investigate this colour reaction but incidentally it was proved to be extremely useful for the detection and analytical determination of minor amounts of several reductant3. The method is based on the reduction of 3r(VI^ to Cr(III) with a sulphite and the subsequent development of its violet complex by a 5min boiling with EDTA in presence of acetic acid at 40 to 50? The colour produced was Rl ' proportional to the amount of sulphite added. This novel colour reaction was further investigated with several other reducing agents such as formaldehyde, hydrazine and ascorbic acid. Colorimetric procedures for the rapid detection and analytical 4aterminations of these substances nere developed.. No colour was observed when EDTA was added to Cr(Vl) under the specified conditions* Among other advantages of the reaction, chromium(III) and chromium(YI) can be determined spectrophotometrlcally in a mixture. The method can be extended to the estimation of nitrite in nitrate and sulphite in sulphate. The system conformed to Beer's law over a wide range of concentrations of the reducing agents. The colour is stable for more than a month. Spot test methods were also developed for several combinations of ions. 176 IV. 7

THE APPLICATIONS OF THE UNDERSTANDING OF SOME THIO-, SELENO AND TELLUROETHERS COMPLEXES ABSORPTION SPECTRA. A'EXTRACTK • -. . 12 1 y / L.R.M. Pitombo', Y. Iamamoto and O.A. Serra y A.M.T.C. 1) Instituto de QuTmica-USP, CP.20780, Sio Paulo, SP, Brasil Départant« 2) Departamento de Quîmica-FFCLRP-USP, Ribeirâo Preto, SP,Brasil Rio de J< The 2-etl rapid at( A simple The greater the understanding of the factors 1,3-hexai

that govern the location and shifting of the Amax of the measurem« complexes, such as the nature of central metallic ion, different acidity, ligands and different solvents, the greater the possibilities of to organ: being able to generalize and make predictions regarding the is rapid absorption spectra of these compounds. From analytical point of in agréer view, it is unnecessary to stress the importance of such constant generalizations and predictions. determin The data obtained in the study of the trans-

MC12(R-S-R1 )2 type, where M = Pt(II) and Pd(II); R •- methyl ; R, = phenyl, o-, m-, and p-tolyl complexes (Y. Iamamoto, O.A. Serra and L.R.M. Pitombo - presented in XVIII ICCC - Säo Paulo, Brazil) were utilized to search for the systematization of the variables, and subsequently extend this to the compounds such as

MC12(R-E-RT)2 type, where H = Pt(II) and Pd(II); R = methyl, ethyl, n-propyl and i-propyl; Rj = phenyl, o-, m-, and p-tolyl; E = S, Se, and Te. Consequently, it was possible to arrive at some generalizations and to delineate predictions regarding locations and shifting of the ligand to metal electron transfer (LMET) band of the referred complexes. 1-CH3pipz other psei; three thec

IV.8 177

EXTRACTION-ATOMIC ABSORPTION DETERMINATION OF TOTAL , -IN SEA WATER ^ /FL0V7 INJECT:

A.M.T.C. Horta and A.J. Curtius 'j.H.Dahl, D

Departamento de Qulmica da PUC/RJ Department < Rio de Janeiro, Brazil 2 Universib The 2-ethyl-l,3-hexanediol has been investigated as a reagent for a rapid atomic absorption determination of total boron in sea water. The rates o A simple chelation and extraction with a 10% solution of 2-ethyl- acetate (CD' 1,3-hexanediol in methyl iso-butyl ketone is followed by absorbance i measurements in an atomic absorption instrument. The effects of metric meas acidity, reagent concentration, extraction time, ratio of aqueous (1973). N.R to organic phase on the extraction were studied. The extraction rates of di is rapid and highly selective. The obtained values for boron are the concent in agreement with a potentiometric method. Also, the distribution ferential k constant of boron in the water/methyl iso-butyl ketone system was 266 (1969)) determined. sible to ca of a new c< described Based on ii the system much simpl: well-defin* of the rea< taken advai ion complex method of in connect: lag phase, well over of the sami degree of method of the concen 1 1-CH3pipz and 284-270 cm- in the 2-GH3pipz) are made by comparison with other pseudotetrahedral Co(II) complexes. For the CoX3(L^) complexes the The auth three theoretically prevedible bending modes are also assigned. Portugal) f

178 IV.9 f. INJECTION ANALYSIS OF ALKALINE EARTH IONS J.H.Dahl, D.Espersen and A.Jensen TITRATIO! Department of Chemistry AD, The Royal Danish School of Pharmacy, A.C. SpTi 2 Universitetsparken, DK-2100 Copenhagen 0, Denmark. I nst i tut(

The rates of dissociation of trans-l,2-diaminocyclohexane-N,N,N}N'-tetra- acetate (CDTA = Titriplex IV®) complexes of magnesium, and Copper ar (th ioglyc strontium ions have been determined using spectrophotometric and polari- napht i1ac metric measurements (A.Jensen and N.R.Larsen, Acta Chem. Scand. 2J_, 1838 and are s (1973). N.R.Larsen and A.Jensen, Acta Chem. Scand. A28, 638 (1974)). The

rates of dissociation of these complexes are very different, enabling Copper ti the concentration of the ions concerned to be determined by means of dif- electrode ferential kinetic analysis (J.B.Pausch and D.W.Margerum, Anal. Chem. 41, (in the p 266 (1969)). However, using this classical method of analysis it is pos- i nd i cator sible to carry out only about 25 analyses per hour. Recently, a concept thymolg1y of a new continuous flow analyser ("Flow Injection Analysis") has been (pH 5,0-7 OV V described (J.Ruzicka and E.H.Hansen, Anal. Chim. Acta ]B.r 145 (1975)). Lead, Cad Based on instant discrete sampling by injection into a carrier stream, or with m the system allows continuous flow analysis to be performed in a fast, er iochrom much simplified way. The discrete instant sampling creates geometrically d ipheny ?< well-defined segments of the sample solution within the flowing stream of the reagent solutions. Furthermore, the authors of this abstract have taken advantage of the fact that the rates of dissociation of the metal ion complexes in question are very different in this segment, i.e. the method of differential kinetic analysis is applied spectrophotometrically in connection with "Flow Injection Analysis". Because of the absence of lag phase, an unprecedented sampling rate for continuous flow analysis of well over 200 samples per hour can be achieved? and even manual injection of the samples allows, under optimized experimental conditions, a high degree of accuracy and precision to be obtained. The variables of this method of analysis will be demonstrated utilizing the determination of the concentration of magnesium, calcium and strontium ions. Further work on these and similar complexes is,at present,being carried out. The authors thank the Instituto Nacional de InvestigacSo Cientffica (Lisboa, Portugal) for financial support.

••~'"K IV. 10 179 MPLEXES I TITRATION OF COPPER AND OTHER METALS WITH TIONALID LIDE. EQ1 M. Molina, A.C. Spfnola Costa, A.M.M. Amorin and J.O. Nogueira Reis Department Instituto de Qufmica da Universidade Federal da Bahia P.O. Box 1

Copper and other metals can be titrated directly with thionalid Compiexe (thiog1yco1ic-13~aminonaphtaIide acid, «-mercapto-N-2- described naphtiIacetamide). Standard solution are prepare in acetonitrile K. V. Mart and are sufficiently stable for titration application. phenyl-sub neva, E.K. Copper titration can be made potenciometrica11y , with a Ag-SCE With 2-thi electrode at best pH range 2-7 or with visual end point detection chelate wh (in the presence of small quantity of TRITON-X-100 to avoid the on solutio indicators adsorption by the precipitate), with indicators picolinean thymoiglycine blue (pH k, 5-6,0), PAR (pH 2,0-7,0) and TAC 5,0-7,0). The pres Lead, Cadmium and mercury (II) can be titrated potenciometrical1y nary syste or with meta11ocromic indicators: PAR for lead (pH 6,0-9,0), Cd(II) per eriochrome black T for cadmium (pH 8,0-9,5) and PAR or 0.100M (Li dipheny1carbazone for mercury (pH 3,5-6,0). ted from p H. S . Ro s s plexes fou Zn(II) (8. constants were also tibility b data is ob

The solid perties of studied by the-ligand trie measu par*d and 180 IV. 11

^COMPLEXES OF NICKEL(II), ZINC(II) AND CADMIUM(II) WITH 2-THIOPICOLINEA- ' A NOVEL ^ySIUDE. EQUILIBRIA IN SOLUTION. ~* FORMATIC M. Molina, C. V. Melios, A. Del'Acqua and E. Trabuco. Makoto 1 Department of Chemistry, F. F. C. L. de Araraquara, UNESP Departme P.O. Box 174, 14800 Araraquara, SP, Brazil. Kyushu t We Coaplexes of thioamides with transition metal ions have already been benzo]-] described (K. V. Martin, J. Am. Chem. Soc. j3£, 233 (1958); F. Lions and alkali n K. V. Martin, ibid. 8£, 3358 (1958)). Later, Cu(II) complexes with some colorime phenyl-substituted 2-thiopicolineanilides were isolated (I. G. V. Glaz- (2) neva, E.K. Mamaeva and A.D. Zeif, J. Gen. Chem. (USSR), jjjj, 1503 (1966)). with pic With 2-thiopicolineanilide (HL) the mentioned authors obtained the CuL, water, t chelate which was characterized from spectroscopic data. Investigations on solution equilibria have not yet been reported for metal ion - 2-thio_ picolineanilide systems.

The present communication deals mainly with equilibrium studies on bi- °2N nary systems comprising 2-thiopicolinaenilide and Ni(II), Zn(II) and Cd(II) perchlorates, in 50% (w/w) ethanol - water medium, at 259C and 0.100M (LiC10,v ionic strength. The overall stability constants, evalua (1) ted from potentiometric measurements (G. Faraglia, F. J. C. Rossotti and Thus, pc H. S. Rossotti, Inorg. Chim. Acta 4_, 483 (1970)), for the parent com- aqueous plexes found (logg^ log£ ; log^) are: Ni(II) (10.01; 18.96; 26.50), 2 acccrdir Zn(II) (8.00; 16.0; 24.7) and Cd(II) (8.06; 15.8; 23.3). The protonation constants of the ligand, in the above mentioned experimental conditions, [21 H H

were also determined (loggj • 11,19 and Iog62 - 12.25). A good compa- The tibility between the computed constants and the pertinent experimental equivoli data is obtained. chlorofc

The solid complexes ZnL? and CdL. have been isolated; some of the pro- 0.017. perties of both compounds indicate their analogy with the CuL, chelate under tJ studied by Glazneva et al. (1966). Complex formation between Ni(II) and The the- ligand under investigation is clearly apparent from spectrophotome- blood re tric measurements. Compounds with other metallic ions have also been pre potassii pared and some of their properties will be reported. insignif ion cone -:*•• g/c I f\ IV. 12 181

' A NOVEL COLORIMETRIC REAGENT FOR POTASSIUM BASED ON CROWN COMPLEX FORMATION Makoto Takagi, Hiroshi Nakamura and Keihei Ueno Department of Organic Synthesis, Faculty of Engineering, Kyushu University, Fukuoka 812, JAPAN We report on the synthesis of a new compound, [41-(picrylamino)- benzo]-15-crown-5 (1) , the natrue of complexation reaction of (2) with alkali metal ions, and the analytical application of (2) as a selective colorimetric reagent for potassium. (1) was obtained by the reaction of (4'-aminobenzo)-15-crown-5 with picrylchloride. Orange powder, M.P. 155°C, almost insoluble in water, but easily soluble in common organic solvents.

NO

(2) HA (2) KA (2) behaves as a weak acid and forms a potassium complex (2). Thus, potassium ion can be extracted into organic phase by shaking the aqueous phase (pH«»12 with Et,N) with a chloroform solution of (2) , according to the following stoichiometry;

[ K+ ] [KA.HA] + aq ovg •aq

The distribution ratio [K ] /[K ] , after equilibrating the equivolumes of aqueous phase containing K (40 - 300 ppm) and

chloroform phase (10 M of (2) and 1 M of Et3N), was found to be about 0.017. Alkali metal ions other than potassium do not react with (2) under the same condition. The colour of organic phase changes from orange (X. 390 nm) to IuclX blood red (X 460 nm) upon complex formation. The absorbace of IltclX potassium complex at 560 nm, where the absorption of the reagent is insignificant, against reagent blank, is proportional to the potassium ion concentration up to 300 ppm. "Sensitivity" according to Sandell is 2 0.64ug/cm . &0 182 IV.13 c POLAROGRAPHIC DETERMINATION OF PLATINUM(IV) THROUGH THE FORMATION OF COORDINATION COMPOUNDS WITH AZIDE ION. Jaim Lichtig and Graciiiano de Oliveira Neto Instituto de QuTmica - USP, CP.20780, Sao Paulo, Brasil

Solutions of Pt(IV), heated with excess of azide, show a characteristic polarographic wave, which can be utilized for analytical measurements. The low electronegativity of azide ion, in comparaison with chloride and the presence of ir* orbitals in the azide ion, allow a back-bonding of the Pt(IV) towards the ligand, giving a great stability to the Pt(IV) azide complex. This stability allowed the development of a very selective analytical procedure and with the exception of Au(III) no other ion of the platinum metal group was found to interfere in the determination of Pt. Au(III), however, can be eliminated by previous extration with ethyl ether, of the chloro- compiexes, as usual. Pt(IV) can be determined in a range of 0.05 - 0.12 mg/ml. IV.14 183 -K 7SPECTROPHOTOMETRIC DETERMINATION OF COPPER WITH N-PHENYLGLICINE

L.Hainberger S,J. and N.de Araujo •/ Depto. de Qulmica, Pontiflcia Universidade Catolica do Rio de Janeiro Rio de Janeiro, Brazil N-phenylglicine forms with Cu a complex which shows a maximum absorbance at 445 run. Beer's law is followed between 0.5 and 2.5 yg Cu/ml, In a volumetric flask, a 0.5% acgueous solutions of N-phenylglicine is mixed with an equal volume, 1/10 th of the volume of the flask, of ammonia 0.05 N and with the almost neutral test solution containning the copper, and the flask is completed with deionized water. After mixing, part of the liquid is heated in a closed test tube at 50° C during 30 mim. After cooling, absorbance is measured in a spectrophotometer at 445 nm. The alkaline metals and alkaline earth metals do not interfere in the proportion 1:100. Pb does not interfere in the proportion 1:10. In the proportion 1:1 the following do not interfere: Cd, Zn, Ag, Mn, Al and W. The following interfere in the proportion 1:1: Ni, Co, Hg, Fe, Cr, Ti, V and Mo. The following anions tested do not interfere at the proportion 1:100: cloride, bromide, nitrate, sulfate and acetate. Phosphate and should not be present. tf/ 184 V.I //fiEODYMIUM(III), SPECTROSCOPIC PROPERTIES OF THE COMPLEXES WITH PKOSPHINE OXIDES AS LIGANDS. 2 o- A.M. Galindo Massabni 1 O.A. Serra' 1} Instituto de QuTmica, UK'ESP, CP.174, Araraquara, SP, Brasil 2) Instituto de QuTmica, USP, CP.20780, Sao Paulo, SP, Brasil

Solid complexes of Nd(III) salts and phosphine oxides were prepared. Chemical analysis, conductance in nitromethane solution and infrared spectra led to the formula: (Cc (L • triphenyl, diphenylbenzyl, dibenzylphenyl, tribenzy? and triethyl phosphine oxides); NdLgX3 (L « trimethy 1 and triethyl phosphine oxides, X « perchiorate and hexafluoro- phosphate); NdL,(N03) (L * triphenyl, diphenylbenzyl, dibenzyl- phenyl, tribenzyl, triethyl and trimethyl phosphine oxides); [NdL-Cl, (PF-.)J (L « triphsnyl phosphine oxide). The coordina- tion of the ligand by the oxygen of the phosphoryl group., 1s evidenced by the reduction of the P-0 bond stretching frequency in 50-100 cm, in relation to the free Ugand; 1n the nitrate complexes these shifts are a linear function of the eletro- negativities of the substituents attached to the phosphous atom. The electronic spectra revealed that the symmetry of the central ion changes from one complex to the another, being probably function of the bulkiness more than any other property of the 3+ ligands. Vo Was possible to infer that NdLfi (L « trimethyl and triethyl phosphine oxides) (J.L. Ryan, Inorg.Chem.8i, 2053 + (1969)) and Ndl4Cl2 (L * triphenyl phosphine oxide) have symmetries near to 0h and D4h respectively. "1

V.2 185 /•

TRIPHENYLTIN-DICYCLOPENTADIENYL-LANTHANIDE COMPOUNDS H. Schumann and M. Cygon Institut fur Anorganische und Analytische Chemie der Technischen Universita't Berlin, Strafie des 17. Juni 135, D-1000 Berlin 12, West-Germany The first compounds containing covalent bonds between the lanthanide elements and tin are prepared by the following methods:

LnCl3 + 3 LiSn(CQH5)3 » Ln[Sn(C6H5)3]3 + 3 LiCl Ln = Pr, Nd, Gd, Er

(C5H5)2LnCl + LiSn(C6H5)3 > (C5 LiCl Ln = Pr, Nd, Gd, Tb, Ho, Er, Yb

(C5H5)2LnCl + HSn(C6H5)3 (C5H5)2Ln-Sn(C6H5)3 + HC1 Ln = Tb, Ho

The chemical and the physical properties as well as the vibrational spectra of the extremely air-sensitive compounds are discussed. The analogous Organogermanium- and Organosilicon-compounds could not be isolated in the same pure state. In both cases the formation of compounds of the type 4| and higher assoziiltes was favoured. :K

beh its the car

4 ur •nd f, 186 V.3

VACTINipE COMPLEXES OP SOME PYRAZOLONE LIGANDS C.G.R. Hair And Jacob Chacko Department of Chemistry Department of Chemistry Birkbeck College University of Kerala London Trivandrum U.K. s. India. There has been a rapid increase in the study of coordination compounds of the lanthanide and the actinide elements. This is indeed justified in view of the diverse uses — from industrial catalysts to colour television — to which complexes of these element* are being increasingly put to. We, herein, report on the synthesis and characterization of some actinide complexes, with formulae:

Th(aap)4(NO3)44H2O Th(aap)3(CNS)42H2O

UO2(aap)2(NO3)2 uo2(aap)2(CNS)2

UO2(dmaap)2(NO3>2 w«2vw...-^/^ 5< (CNS)2

UO2(ap)2(NO3)2 UO2(ap)3(CNS)2 These have interesting structural features, which might well prove to be of technological relevance. Three related pyrazoione ligands of physiological importance viz., l-phenyl-2,3-dimethyl-5-pyrazolorie (antir ine - ap), 4-aminoantipyrine (aap) and 4-dimethylaminoanti- pyrine .dmaap) were chosen for the study. Complexes of these ligands 4+ + with 1h and U02 ions have been synthesized and characterised by physicochemical methods such as conductivity and magnetic suscepti- bility measurements, infrared spectroscopy and by thermoanalytical methods (TG, DTG and DTA). stereochemical aspects have been explored using two different anions: the linear thiocyanate ion and the non-linear bulky nitrate ion, both affording possibilities of bidentate bonding. While the NO^ ion behaves unidentately towards Ih +, it acts as a bidentate ligand in the case of the uranyl complexes. The thiocyanate ion coordinates through S in the uranyl complexes, but in the Th complexes it coordinates through N and behaves as a'soft base1. As for the ligands, both antipyrine and its 4-amino derivative are found to be unidentately bonded through the carbony1 oxygen whereas 4-dimethyl aminoantipyrine uses both the carbony1 oxygen and the exocyclic tertiary nitrogen for coordination. All the complexes, except the uranyl thiocyanate complex of 4-dimethyl aminoantipyrine, are found to be non-electrolytes. ih« uranyl-dmaap-thiooyanate complex exhibits ltl electrolytic behaviour and it may be formulated as (CNS) J £"vo (dma*p) g_7. 4 2 ab s1

M •0

V.4 187

UNTHANiÜE^P-ERCHLORATE COMPLEXES WITH 2,2 '-SULFINYL-DIPYRIDIME E. Gies brecht and Abel de Oliveira Instituto de Quîmica - USP, CP.20780, Sao Paulo, Brasil

Some results describing the reaction of dipyridyl type

1 i gands : X « CH2, S, S02, CO, NH and others

with transition metal ions and with uranyl ion have been recently described (W. R.McWhinnie, Coord. Chen.Rev., 5, 293 (1970); G. C. Pappalardo & A.Seminara, J.inorg.nucl.Chem., ZB, 1993 (1976)). It is also known that lanthanide (III) ions form stable complexes with ligands containing N^ or £ (see reviews from J.H. Forsberg , Coord.Chem.Rev., l_0, 195 (1973); J. Gopalakhishnan & C.C. Patel, J. Sei. Ind. Res., £7. 475 (1968)). In this paper the preparation and properties of compounds of the genral formula Ln(C104)3.8 sdpy are described in which Ln • lanthanide and Y, and

sdpy

The complexes form very stable, isomorphous. crystals, melting with decomposition above 200°C. Infrared spectra show evidences of coordination through the oxygen atom of the SO group (shift of vSO from 1030 to 980 cm"1); the pyridine ring frequencies remain unchanged (at 1570, 1445 and 1000 cm ). The CIO^ Ion bands are the same as in the free ionic form (Tj). Conductance measurements in acetonitrile and nitromethane solutions show a 1:3 behavior. The fluorescence spectrum of Eu(III) and the visible absorption spectrum of Nd(III) compounds show evidences of à high site symmetry probably a distorced cube. It is possible that weak interactions with the pyridint rings occur to account for the high symmetry and coordination ntmber. 188 V.R.I Fi ADDUCTS OF LANTHANIDE PERRHENATES AND THIOXANE-OXIDE (TSO)* A.M.P.PELIClSSIMO, G. VICENTINI and L.B. ZINNER Instituto de Qulmica, Universidade de Sâo Paulo, Caixa Postal 20.780, Sao Paulo, Brasil

Adducts between lanthanide salts and cyclic sulphoxides are been sys_ tematically investigated in our laboratories. In this communication we wish to describe the addition -compounds of lanthanide perrhenates and thioxane-oxide. The compounds obtained with composition LnfReO,),. 4TSO (Ln= La-Lu, Y) were characterized by elemental analysis, infrared and electronic spectra, conductance measurements in methanol and X-ray powder patterns. 1] According to the infrared spectra the following may be concluded: a) the compounds do not contain water bands; b) the ligand in bonded to the tripositive lanthanides through the sulphoxide oxygen, because a shift of the S=O stretching mode to lower frequencies, in relation to the free TSO, is observed, also, splittings of this vibration are showed in the spectra; c) the antisymmetric and symmetric» C-O-C stretching vibrations are not modified in relation to the free ligand, 1( indicating that the etherical oxygen is not coordinate to the 1( rare-earth ions; d) the data for the ReO. ions may indicate that, at 1( least in part, they are coordinated. Conductance measurements are in accordance with a behaviour of 1:1 electrolytes. X-ray powder patterns show that: a) the compounds from to are isomorphous; b) complexes from to thullium and form a second series and -c) and present the same pattern.

* Supported by PAPESP C

Friday, July 22, 1977

Room A Room B

9.00 h I. Fragalâ S. Volkov 9.20 W.L. Jolly B. Lenarcik 9.40 R. Massart E. Rizzarelli 10.00 R.G. Goel H. Sigel 10.20 J.G. Riess R. Barbucci 10.40 U.C. Bradley W.A. de Oliveira B. J.-Trzebiatowska R.D. Hancock

11.15 E. Giesbrecht

Room C Room D

9.00 E. Boschmann C. Airoldi 9.2Ö ^ E.A. Neves G. Anderegg 9.40 L.R.M. Pitombo R.D. Hancock 10.00 J. Rèedijk H.B. Silber I •/ 10.20 K. Srinivasulu |s.L. Davydova 10.40 G.R. Choppin N.A. Kostromina G. Vicentini ( IA

Si I w

*;; Friday, July 22, 1977 Room A Room B W 14.00 h H.M. Yabukov "H F.G. Gallais 14.20 A.M. Golub H 14.40 A. Nettle Z. P. Zannini _^L 15.00 H.H. Ulbrich J. Dehand r^F" 15.20 0. Reinen K. Schowochau I^B L.M.M, de Matheus M.A. De Paoli H Some 16.00 E. Weiss H. Behrens ^| prep 16.20 H. Ohtaki J. Galy m solu 16.40 M.C. Mattos CA. Reed • for 17.00 B. Krebs J.L. Boucher • : The 17.20 H.L. Nigam J.J. Ziojfkowskï to I j disa 17.40 K.E. Bessier S. Jeannin • D. Reinen i 1 1 Room C Room D i H 14.00 O.A. House G. Vicentini H 14.20 H. Keim V.K.L. Osorio H 14.40 M.N. Sastri N.K. Bavidenko ^M 15.00 C. Battistoni M.A.F. Gomes ^m 15.20 M.M.A. Sekkina L.B. Zinner ^m M.L. de Castro A. Janowski ^Ê J.A.P. Holanda ^M i 16.00 6.S. Mironov S.P. Sinha ^M ' 16.20 D. Banerjea 16.40 , S.A. Neves P. Porcher ^M 17.00 H.E. Toma G.F. de Sa ^m 17.20 B. Tomazic L.C. Thompson ^Ê 'i 17.40 Yu.A. Bus1ayev A. Janowski ^M 8 M.E.M. Helene G.F. de Sa 3 ! r

11.32 0 189

KINETIC STUDIES OP THE "SIX-MEMBERED RING EFFECT11

D. A. House Department of Chemistry, University of Canterbury, Christchurch, New Zealand

An increase in the rate of aquation of CoClgdO* or CoCKN-)2"1" complexes is observed when 1,2-diaminoethane (en) is replaced by 1,3-diaminopropane (tmd) (M.C. Couldwell, D.A. House and H.K.J. Powell, Inorg. Chem., 12, 627 (1973))• This effect is not manifest in the analogous (and in many cases, isomorphous), Cr(III) complexes (D.A. House, Inorg. Nucl. Chem. Lett., 12, 259 (1976)). 2+ Some cis-CoCl(tmd)2(A) (A = ammonia, methylamine, benzylamine) have been prepared and the rates of chloride release have been measured in acidic solution. These data will be compared with similar data previously obtained + for the well known cis-CoCl(e.Ti)2(A) complexes. The origin of the "six-membered ring effect" for Co(III) complexes is attributed to the ease of distortion to a trigonal bipyramid transition state via a dissociative mechanism. 0 1 190 J 0 11.33 EFFECT OF PRESSURE ON REACTIONS OF PALLADIUM(II) COMPLEXES D. A. Palmer, M. Mares, and H. Kelm

Institute of Physical Chemistry, University of Frankfurt, Robert Mayer Strasse 11, D 6000 Frankfurt/Main, FRG.

As a rule, substitution reactions of square planar complexes obey a two- term rate expression of the form

kobs. - k1 + k2 M It is commonly accepted that in this equation both rate constants repre- sent bimolecular processes involving the complex and either a solvent or a nucleophile (Y) molecule. However, recent studies indicate that a dis- sociative pathway can exist and may even dominate under certain condi- tions, e.g. when substitution inert ligands in the complex sterically hinder the approach of a potential nucleophile.

A study of the effect of pressure on the rates of substitutions in + rPt(dien)X} complexes has shown the k2 path to be associative in nature. No definite conclusions could be drawn from the AV values for the k- path.

By the addition of substituent N-alkyl groups to the (dien) ligand a pseudo octahedral configuration is forced on the complex possibly changing + 4 its chemistry. Indeed, fPd(Et4dien)xJ reacts ca. 10 times slower than the unsubstituted (dien) analog and the k2 path is in many cases elimi- nated. Our pressure studies show a distinct trend in AV values exists for the substutution reactions of [pd(Et4dien)xJ complexes as X is varied through the series Cl, Nv Br, I, SCN, NCS and NH.,. These values become less negative along this series and parallel an increase in 4 G. Obviously bond breaking plays an important role. In fact, by comparison of the AV* and corresponding AV values an associative interchange mechanism, I , can be assigned to these reactions.

The lack of a marked solvent effect on 4 V tends to refute the claim that the reactions are dissociative in dipolar aprotic as opposed to protic solvents.

The virtually identical values of AV for linkage isomerization of rPd{Et4dien)SCN] and its substitution reaction with Br" ions imply that the same mechanism, I , is involved here. M

11.34 191

ACCELERATING EFFECT OF ION ON THE FORMATION OP CHROMIUM (III) - J2DTA COMPLEXES FROM OXALATO COMPLEXES OF CHROMIUM (III) • 7. Ananta Ramam and M.N. Sastri Department of Chemistry, Andhra University, Waltair53O 003,INDIA, It was shown earlier that bicarbonate ion accelerates the rate of hexa-aquochromium (III) - EDTA reaction (V.K.Rao, D.S. Sundar and M.N. Sastri, ChemistTAnalyst %±, 86 (1965); Z.anal.Chem., 218. Band, 2.Heft, 93 (1966) ). A similar catalytic effect of bicarbonate ion on the substitution of oxalat£ complexes of chromium (III) by EDTA has be_ejL5tud_ieji. A mechanism is proposed for the substitution process. 1 192 11.35

^/REVERSIBLE REDUCTION REACTIONS OF SOLID SOLUTIONS OV MOLYBDENUM AND RHODIUM OXIDES

C. Battistoni, A. La Ginestra, G. Mattogno and E. Migliozzi

Laboratorio di Teoria e Struttura Elettronica del CNR,Roma(Italy) Iatituto di Chimica generale, Universita di Roma (Italy)

Following the preliminary results on the reduction behaviour of rutile-type solid solutions of rhodium and molybdenum oxides (A. La Ginestra et al., Gazz. Chim. Ital.,103(1973)963), we report the ESCA spectra of a series of compounds obtained by reduction of solid solutions (having different Mo/Rh ratios) with !J or CO and successive oxidation with air or CO , It can be shown that the reduction and re-oxidation processes take place in different ways depending on the reaction temperature and on the Mo/Rh ratio in the initial compounds. When this ratio is lower than 0.3 the compounds are a mechanical mixture of Rh 0 and MoO and the ESCA spectra show that reduction- with H takes place at much higher temperature than that for the compounds with a Mo/Rh ratio between 0.3 and 0.6 (for which mixed oxides with a rutile-type phase is formed). For compounds with composition lying in the above range, a comparison between the b.e. values of the initial and final compounds and those of metallic Mo and Rh show that only when the reductant is H_ can a reversible re-oxidation process take place (both with air and CO ), leading to the formation of the_ rutile-type phase together with some amount of metallic rhodium. When the reduction is carried out with CO, it leads to the irreversible formation of metallic Rh and Mo, perhaps accompanied by the decomposition of excess CO to carbon and carbon dioxide. MICROCOPY RESOLUTION 1 ESI CHART NA1IONAL BURIA1J Of SUNDANO* ]9ln A

ELECTRICAL PROPERTIES OF Co(II), Ni(II) AND Cu(II) COMPLEXES OF MERCAPTOBENZOTHIAZOLE T.H. Salem and M.M. Abou Sekkina Department of Chemistry, Tant University - TANTA, Egypt - A.R.E.

The present investigation aims to evaluate the mechanism of ele-trical conductivity of mercaptobenzothiazole complexes of Co(II), Ni(II) and Cu(II) in the temperature range of 298 - 4189K and relate the mechanism to the physico- -chemical properties of these complexes that not recorded in the literature.

The prepared Co(II), Ni(II) and Cu(II) complexes possess semiconducting properties in the investigated temperature range. On going from Co or Ni - complexes to Cu - complex the electrical conductivity increased and the activation energy decreased from ^4.0 up to 2.0 ev. This was attributed to the formation of bridge between the two ligands and the metal ion facilitating the transfer,of current and to the increased number of electron of the d-sublevel in the same direction. I 194 II.R.7 RETARDATION OF THE FERRIC ION CATALYZED DECOMPOSITION OF HYDROGEN PEROXIDE BY TRIS(GLYOXALBIS(METHYLIMINE)IRON(II) Marina Lessa de Castro and Helena Li Chum Instituto de Qulmica, Universidade de Sao Paulo, Sao Paulo, Brazil

+ The complex tris(glyoxalbis(methylimine))iron(II), FeG3 , undergoes ligand-oxidation when oxidized by cerium(IV) at low acid concentration,

e.g., [H2SO4J<10M, yielding stable ligand-oxidized complexes (H.L. Chum and P. Krumholz, Inorg. Chem., 13, 514, 519 (1974)). When added to the

system H2O,/Fe(III) the complex strongly retards the decomposition of hydrogen peroxide and the rate of oxygen evolution, in the pH range from

1 to 2.5, at 25 - 35°C, in conditions where [H2O ]» [Fe(III)]> DPeG^ . At the same time, this colored compound is destructively oxidized yielding colorless species, at a rate which is independent of the complex, concentration. After the disappearance of the colored species the decomposition of H-O- catalyzed by Fe(III) ions is observed.

This retardation can be explained on the basis of the free-radical mechanism proposed by Barb et al. (Trans. Faraday Soc, 4_7, 591 (1951))

for the decomposition of H00, by Fe(III) ions, assuming that the radicals z 2+ 3+ " " - - - can oxidize FeG, to FeGg . The oxidized complex undergoes a very fast intramolecular reduction to the ferrous state with concomitant oxidation of the ligand. The stoichiometry of the reaction in terms of moles of 2+ H-O- consumed per mole of FeG^ can be related to the average length of the free-radical chain. In the presence of the complex this length is increased by two orders of magnitude, indicating that the complex enters the chain process several times. The kinetics and the possible mechanisms for this reaction will be discussed.

Acknowledgment: Financial support from the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo is gratefully acknowledged. L -J

C IJ-37 L '/ y/ ^ / UK COMPLEX FOE :ATION IN CEHTAIN iHIEDEL-CRAJTS REACTIONS v Yu. A.Moskwitchev, G.S.Mironov. S.K.Kramerova Yaroslavl Polytechnical Institute, USSR.

Problems of complex formation in the reaction of aromatic compounds sulfonylation with certain substituted pbenylsulfochlorides on Pe chloride catalyst were irvestigated. Kinetic methods showed that th.f5 initial compounds :-nd the reaction product (diarylsulfone) form inactive complexes with the catalyst. This results in competitive reaction inhibition ^-ith all compounds mentioned. Kinetic studies allow 3d to 'naxe quantitative evaluation of inhibition phenomenon and calculate the coordination numbers of complexes. The effect of certain substituents in para-substituted phenylsulfochlorides and ';iono-and- di para—substituted diarylsulfones on complexing stabi- lity of these compounds with the catalyst was also studied. Positive correlation of inhibiting ability of the series of compounds men- tioned with HaiTmet 6 - constants was found. Investigation by NMR- ^nectroscopy and kinetic methods showed that complexes are formed through donor-acceptor interaction of Fe chloride with the oxygen atoms of sulfonyl groups. The investigations performed allowed to explain apparent anomalous effects in reactivities of certain, para- substituted phenylsulfochlorides in the process of sulfonylation. 0 196 • *\L 11.38

KINETICS AND MECHNISM OF SEDUCTION OF TRIS(ACETYLACETONATO)-COBALT(III) AND TRIS(OXALATO) COBALTATE(III) ION BY HYDRAZINE, HYDROXYLAMINE AND FORMATE IN ACID MEDIA, D. Banerjea and A.K. Basak

Department of Chemistry, Inorganic Chemistry Division Unive-sity College of Science, Calcutta 700009, India

Th< The rates of reduction of the cobat(III) complexes by the reducing agents in tr< acid(HC10,) media have been determined spectrophotometrically at different th< concentrations of acid (0.5-1.0 M) and reducing agent (0.04-0.2 M) at different ca1 temperatures (in the range of 30°-60°C) at constant ionic strength (I, 2M). Both poi the complexes and their protonated species have been found to undergo reduction Th< by the reagent dependent path concurrent with the acid catalyzed intramolecular self reduction of the complex according to the following general rate law: + anc Rate - -^kjj [H J + ^ + k^R TH*J ) [Rjj ^Complex] sei where kj, is the specific rate constant for the acid catalyzed self reduction of the complex, kp is that for the reduction of the complex by the reductant and k R for the protonated form of the complex by the reductant (the reriuctants are all th« present in their protonated forms at the acid concentrations used). Both for k,, act and kg the plot of AH vs. AS is linear for any particular complex az: and different reducing agents and this isokinetic relationship suggests a

similarity of mechanism in all the cases. Again, the plot of log k_ or log k- R for Co(acac). vs. corresponding value for Co(ox), for the different reducing agents is linear with a slope much greater than unity suggesting inner sphere mechanisms for all. * 1 ^

11.39 {tt>#p%s 197 /

if/ CATALYTIC WAVES WITH AZIDO-COMPLEXES

Eduardo de Almeida Neves and Roberto Tokoro Department of Chemistry - University of Sao Paulo P.O. Box 20780 Sao Paulo Brasil

The azido-complexes of cobalt(II) when present in a supporting elec- trolyte containing N7/HN, buffers give rise to catalytic currents at the dropping mercury electrode. Many factors were studied. Maximum catalytic activity was attained at 0,4 M azide concentration corres- ponding to the average ligand number of 2. The products of the electrode reactions were analysed in solutions electrolyzed in constant current or controlled potential conditions and the volume of gases measured. It was foimd that the process re- sembles an antecipation of hydrogen discharge, however the main reac

tion is the fast reduction of HN3 to NH4 cations by the thermodyna- mically unstable cobalt(I) complexes formed on the electrode during the reduction of cobalt(II) complexes. The kinetics of electrode re- action was studied. Catalytic activity was observed also with other azido-complexes, specially those of nickel(II). 4.7 ^"U02 (dma^p)3_7.

198 11.40

^/PROPERTIES AND REACTIVITY OF POLYNUCLEAR RUTHENIUM-IRON COMPLEXES Henrique E. Toma Instituto de QuTmica, Universidade de Sao Paulo Caixa Postal 20780, Sao Paulo, Brazil

Reported Is a study on the chemistry of the linear tr1- nuclear complex b1s-u-pyraz1ne-trans-tetraamm1neruthen1um(II)bis- pentacyanoferrate(II).

NC CN H,N NH, NC CN 4- \/ fr =* \/ NC—Fe—N( ^)N—Ru—N v V( ) N—Fe—CN /\ N^: -u / \ NC CN 6 H,Ni\ NH \, ^ NC CN

The consecutive kinetics of formation and dissociation of the trinuclear complex and of the Intermediate binucTeaf^cennprteTr were Investigated at their Isosbestic points: 545 nm and 504 nm, respectively. For the binuclear and trinuclear complexes, the specific rates of formation, &H* and AS* were 6.8x10 W"s"' ; 15.1 Kcai.mol"1; 10 cal .noV^.deg'1 and l.eTxlO^iT1" ; 14.3 Kcal.mol"1; 4 cal.mo! .deg" For the dissociation reaction, the specific rates . AH< and AS* were 5.7xloWW; 28.6 Kcal.mol ; 22 cal.mol" .deg" and 1.32xlO"4M"1s"1 29.6 Kcal.mol -I 27 cal.mol" .deg" , respectively.

The electronic spectra of the complex at several 4H oxidation states were recorded In J^O^ Evidence for Intervalence 2° transitions was observed in the near Infrared region. A simplified MO scheme 1s proposed for the trinuclear complex. The mixed valence chemistry of this system 1s discussed based on electronic spectra and cyclic voltammetry data. absorption spectrum of Nd(III) compounds show evidences of a high site symmetry probably a distorced cube. It is possible that weak Interactions with the pyridine rings occur to account for the high symmetry and coordination nimber.

/ // Y $ / 11.41 199 "V DISSOLUTION AND TRANSFORMATION OF URANYL PHOSPHATE IN AQUEOUS SOLUTIONS Branko Tomazic •-- Center for Marine Research, "Rudjer Boskovic" Institute Zagreb, Croatia, Yugoslavia The mechanism and kinetics of dissolution and crystal growth of uranyl %4H is of phosphates, UO2HPO4'4H2O and (UO2)3(K>4)2 2° considerable interest- A complete understanding of these processes will find wide application in the technology of uranium production from low grade uranium ores. The dissolution of uranyl phosphates in diluted solutions of perchlo- ric and phosphoric acid were followed kinetieally by using a highly re- producible experimental procedure. It has been shown, that the process of dissolution of UO2HPO4>4H2O in phosphoric acid is simple, tempereture dependent rate process, which can be characterized by well known kinetic relations. However, the dissolution of UO_HPO -4H2O in perchloric acid appears -to be complex, surface controlled reaction. After a pseudoeguili- brium condition, which is characterized by 1:1 dissolution stoichiometry a rapid solid phase transformation occurs. This has been studied by a number of physico-chemical methods (chemical analysis, i.r. spectroscopy, scanning electron microscopy (SEM), specific surface area determinations).

TTie "incongruent" dissolution of U02HP04'4H20 results in the complete transformation into less soluble (UO )3(PO )2«4H O phase. This behaviour can be interpreted as a consequence of complex equilibria. Under the experimental conditions in perchloric acid medium, uranyl ion is only partially complexed with phosphate ion, and therefore, after an appropri- ate induction period, the formation of highly insoluble (U00)-_ (PO.) _'4H 0 takes place. As shown by SEM, no surface nucleation occurs during the process of transformation. As expected, the dissolution of (UO2)_(PO4)2

4H20 appears to be simple, temperature controlled rate process, with 1.5:1 dissolution stoichiometry.

The presence of various additives in the U02HP04-4H20 dissolution system (phosphonates, polyphosphates, FeCl,) can completely inhibit the

-formation of (UO2)3(PO )2'4H2O, due to different reaction mechanisms, as a consquence of very pronounced ability of uranyl ion to form coordination complexes. 200 11.42

V/LIGAND TRANSFER IN OCTAHEDRAL COMPLEXES OF d° - SLEMENTS Yu.A.Buslayev and Yu.V.Kokunov Institute of General and Inorganic Chemistry, Academy of Science of the USSR, Leninaky proapeCG 31, Moscow, USSR The neutral fluoro-complexes of tungstaa-, niobium and with OH-containing ligands transform into anionic complexes with the amine added (Yu.A.Buslayev and Yu.V.Kokunov, Koord.Khim. 2,1360/1976/). In the compouncls [wXF^OCHgCHgOHJ] (X isiO,sS) (I) oxygen atoms of the (-OCHgCHgOH) group are in the cis-titT-bond) and trans-position (donor- acceptor bond) to the multiple-bonded ligand X. Amine being added to the solution (I) complex cis-fwiF^OCHgCHgO)]" is formed with two oxy- gen atoms of the (-OCHgCHgO-) group in cis-position to the multipite bond W=X. In the complexes WXP^LCLsROH.HOCI^CHgOH) OH-containing ligand occupies trans-position with respect to the multiple bond. The increasing basi- city of the solution leads to the formation of anionic complexes [wXP^(OR)]" or [iXF^/OCHgCHgOH)]" with OR and OCHgCHgOH groups occu- pying cis-position to the multiple-bonded ligand. If amine is added to a solution complex trans- JMF^(OBt)EtOH] (M=Nb,Ta) transforms into complex anion cis-JMF^^Et),^" as a result of protic dissociation. •*&m*t The complexes [w2!P,(OR)p3"' with two OR groupallocating-In the equato- rial plane of the "octahedron in cis-position to eash other have been obtained by adding amine to a solution of [WXFJ(OR)ROH], the group OR and the molecule ROH being in cis- and trans-positions to the multiple bond. The transformation of the neutral complexes into anionic complexes as a result of protic dissociation of the coordinated molecular ligand or hydroxo-group of the ethylenglycole is accompanied by the formation of € -bond between metal atom and oxygen atom of the acido-ligand, the change of oxygen-containing ligand bond character with the central atom ft*TiriTte *he acido-ligand transfer into the equatorial plane of the octahedron, while one of the cis-fluorine atoms transfer in trans- position to the multiple-bonded ligand (or OR-group). ©I > m 5 IL

II.R.8 201

KINETICS OF THE OXIDATION OF TRIS(GLYOXALBIS(METHYLIMINE))IRON(II) BY CERIUM(IV): ACIDITY AND TEMPERATURE DEPENDENCE Maria Elisa Marcondes Helene and Helena Li Chum Instituto de Qulmica, Universidade de Sao Paulo, Sao Paulo, Brazil.

2+ The oxidation of tris(glyoxalbis(methylimine))iron(II), FeG3 , by cerium(IV) yields stable ligand-oxidized complexes. The primary step is

the oxidation of the metal ion to FeG3 . The rate-determining step is

the disproportionation reaction of FeG3 yielding ligand-oxidized complexes and regenerating the original ferrous complex. The experimental 3+ 3+ 2 3+ rate law is -d[FeG3 J/dt = k[FeG3 ] + k'[FeG3 ], where the first 3 1 1 term on the r'.h.s. is dominant. In 4.0 M H2SO,, k = 2.0xl0 M~ s^ and k1 » 5xlO~ s (H.L.Chum and P. Krumholz, Inorg. Chem.,13,514,519(1974)). A detailed mechanism proposed for this reaction shows the importance of water and proton activities:

FeG G + H PeG3 + H2O , 2 * 3°

3+ 2+ FeG H2O FeG2GA

2+ 3+ 3+ FeG2GA FeG 1*-> FeG2GA

where G =H3CN=CH-CH=NCH3J G*=H3CN=C-CH=NCH3. or H2CN=CH-CH=NCH3 j GA + H3CN=C (OH)-CH=NCH3 or H3CN=CH-CH=CH2OH. Assuming k ,[H3O 1» FeG + 2+ k2 H 3 ] [H2C[J, and steady-state concentration for FeG2G and FeG2GA 33+ 3 we obtain: -d[FeG3 ]/dt 2k2K Some examples of the dependence of the overall rate constant on water and proton activities are shown:

k obs — x 10 » M -HC 2.0 4.0 1.77 0.725 1.2 4.5 2.01 0.650 0.72 5.0 2.25 0.604 0.19 6.0 2.69 0.475 The observed second-order rate constants exhibit a linear dependence 0X1 a / aH 0+ within the H2° ' 3 experimental error. These results corroborate the proposed reaction mechanism. The temperature dependence of k obs will be presented.

Acknowledgment^ Financial support from the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo and from the Conselho Nacional de Pesquisas is acknowledged. M.E.M. Helene G.F. de Sa

202 III.a.28 ty He(I)/He(II) photoelectron spectra(ps) of dn (7£n"£ 10) tetracoordinated complexes. 7 I.Fragala, E. Ciliberto and G. Condorelli Istituto di Chimica Generate, Universita di Catania, V.A.Doria 6 Catania Italy

The question of the bonding in the tetracoordinated transition metal complexes, though studied through various experimental or theoretical approaches, is far away to be well understood. Preliminary ps studies(G.Condorelli et al.,Inorg.Chim.Acta,7 (1973)725)indicated the upper filled molecular orbitals to be mainly located on the ligand framework. On the other hand, this experimental pattern is not an exceptional case having been reported ps data on a wide class of'd'or'4f'inorganic derivatives were the partly antibonding filled shells have ionization energies(IE)higher than their bonding counterparts. Moreover, looking through literature ps data on some tris ($-dichetonate) derivatives of the first row transition elements, the tendency to have'internal'd ionizations parallels the lowering of the nephelauxetic ratio. Co< Fe < Cr That the relative ligand-metal nephelauxetic ratios play a determinant role in relation to the electronic structure can be deduced from the fact that 'external'd ionization cannot be detected for Co(acac), while they lie'external1 in Co(dtp),. In terms of symmetry-restricted covalence the nephelauxetic ratio is expected to be more important the better the metal-ligand energy matching . This effect will become more relevant on going along each transition series due to the stabilization of the d levels. To get a better rationalization on the above problems we studied He(I)/He(II) ps of tetracoordinated complexes of the title divalent cations with a very wide class af ligand anions namely: dipivaloylmethane;dimethylglyoxime;N,N'-bis(salicylidene) -l,3-propylendianinejN,N'-ethylene-bis(acetylacetoneimine);N-t-buthylpyrrole-2- aldunine;2,2'-propylene-bis(nitrilomethylidine)dipyrrole;diethyldithiophosphate; diethyldithiophosphite. PS data indicated the electronic structure of the title complexes to be well described in MO terms rather than in conventional ligand field ones. 7 III.a.29 203 &/

X-RAY PHOTOELECTRON- SPECTROSCOPY OF METAL CARBONYL COMPOUNDS

W. L. Jolly and S. C. Avanzino

Department of Chemistry, University of California^and Materials and Molecular

Research Division, Lawrence Berkeley Laboratory, Berkeley, California 94720, U.S.A.

Back-bonding in a transition metal carbonyl involves a decrease in the C-0 bond order and an increase in the negative charge of the oxygen atom of the carbon monoxide ligand. Heretofore the only physical property which has been broadly applied as a measure of such back-bonding is the C-0 stretching frequency

(or the derived force constant). We now have XPS data for a wide variety of transition metal carbonyl compounds in the gas phase which show that the oxygen

Is binding energy can be used as an easily-determined reliable measure of the degree of back-bonding. These binding energies are linearly correlated with the corresponding multiplicity-weighted C-0 stretching frequencies. We have been able to deconvolute the 0 Is spectrum of Fe(CO)s into two bands consistent with stronger back-bonding in the equatorial CO's than in the apical CO's. solvents. The virtually identical values of A V for linkage isomerization of fpd(Et.dien)SCN]+ and its substitution reaction with Br~ ions imply that the same mechanism, I , is involved here.

204 III.a.30

P NMR STUDIES ON W AND Mo HETEROPOLYCOMPOUNDS: CORRELATION BETWEEN CHEMICAL SHIFTS STRUCTURE R.' Massart, R.1 Contant, J.'M.1 Fruchart, J,1?,' Ciabrini and M.' Fournler Laboratoire de Chimle des metaux de transition (ERA n° 608), University Pierre et Marie Curie, 4 Place Jussieu, 75230 Paris Cedex 05

In the case of heteropolycompounds with phosphorus as central atom, 31P NMR studies have been recently carried out.' However only few compounds were concerned and no satisfactory correlation between chemical shift and structure has been proposed.* This study which deals with 24 compounds was thus undertaken in order to correlate more exactly chemical shift and structure and to bring more light on the properties 3- of the different heteropolyanion series.* The complexes are related to the (PM120,Q) series and to the (p2M18°62^ " series» with M = W and Mo, and to mixed heteropolyanions obtained by the removal or partial substitution of the metal element.' It is likely possible to explain chemical shift variations in terms of variation of electronic density surrounding the phosphorus atom.' A good correlation between the frequency of tetrahedron vibration (V P - 0) and the corresponding chemical shift value is shown: the weakening of F - 0 bond corresponds to a decrease of the oxygen screen effect.' For those compounds containing several 1? atomsj the existence of one or several peaks allows to suggest a structure. Using o values considerations the positions of holes or substituent elements are determined.1 III. a. 31 205

TRIS(t-BUTYL)PHOSPHINE COMPLEXES OF SILVER(I). PREPARATION, STRUCTURAlr,) CHARACTERIZATION AND SPECTRAL STUDIES R.G. Goel and P. Pilon

Guelph-Waterloo Centre for Graduate Work in Chemistry, University of Guelph, Guelph, Ontario, Canada NIG 2W1.

Tertiary phosphines form tetrameric 1:1 complexes with silver halides. Crystallography studies show that these complexes adopt a cubane like or a chair like structure in the solid state [B.K. Teo and J.C. Calabrese, Inorg. Chem., 15., 2467 and 2474 (1976); M.R. Churchill, J. Donahue and F.J. Rotella, Inorg. Chem., 15., 2752 (1976)]. The complex PrrjPAgSCN is polymeric with a distorted tetrahedral configuration around silver [C. Panattoni and E. Frasson, Acta Cryst., 1£ 1258 (1963)]. jln this paper we report on hitherto unknown monomeric tertiary phosphine complexes containing two-coordinate silver. Reaction of BU3 with AgX (X = Cl, Br, I, CN and SCN) afforded complexes of the type BuqPAgX. Molecular weight, conductance and P NMR spectral measurements show that all the five complexes have a monomeric two-coordinate structure in solution. The Raman spectra of the complexes in the solid state are very similar to those in solution indi- cating that the two-coordinate mouomeric structure is maintained in the solid state. t t The complexes Bi^PAg^Oj) and Bu3PAg(0Ac) also behave as molecular monomeric species in solution. The infrared spectral data indicate that the nitrate complex has a two- coordinate structure in the solid state whereas the acetate complex is indicated to contain three-coordinate silver. Reaction of BU3P with AgX salts where X » CIO4, BF4 or PFg, gave two-coordinate cationic complexes of the type [(BugP^AgjX. Unlike less bulky phosphines, BU3P does not form complexes in which sore than "two'ptrosphlnes-areco- ordinated to silver(I).

Far-infrared, Raman, H and P NMR spectra of all the complexes have been studies and the Ag-P and Ag-X stretching frequencies have been assigned. The symmetric Ag-P stretching frequency for the cationic complexes occurs at ca. 95 cm" ; for the BuoPAgX 31 complexes this frequency varies with X. A recent P NMR study showed that the phosphorus ligands in the silver (I) complexes of (EtO^P and (p-tolyl^P are labile above —70°. [E.L. Muetterties and C.W. Alegranti, J. Amer. Chem. Soc, j)4_, 6386(1972)1. 31 In marked contrast to these results, the P NMR spectra for the tris(t-butyl)phosphine complexes of silver(I) showed Ag- P and Ag- P spin-spin coupling at ambient temperatures. The JAg-P values for the cationic complexes are very sinilar but the JAg-P values for the molecular complexes show a marked dependence upon X. The for- mation of two or three-coordinate non-labile silver-phosphine complexes in the present work- can be attributed to the large steric requirement of. Bu,P. , the irreversible formation of metallic Rh and o, per aps

accompanied by the decomposition of excess CO to carbon and

carbon dioxide.

206 IHIkA.32

-/ METAL-ALKYL AND METAL-ARYL INTERACTIONS IN SOME PALLADIUM(II) HTDRAZONE COMPLEXES.

M. Postel, M. Pfeffer"1" and J.G. Riess, o/Claudio 1

Laboratoire de Chimie Minerale Moleculaire, Equipe de Recherche Associe'e au CNRS, Departaoei Universite de Nice, Faculte des Sciences, Pare Valrose, 06034 NICE-CEDEX, France, and Laboratoire de Chimie de Coordination, Laboratoire Associee au CNRS, 1 rue Blaise Pascal, 67008 STRASBOURG-CEDEX, France.

Substituted hydrazines, when coordinated to palladium, react with organic ketones to give hydrazones which remain coordinated to the metal throught the condensed nitrogen.

With aromatic ketones, further attack of the metal on the "ketone's phenyl group leads to orthometallated type I compounds [PdClArNR NRJl,]-, while with aliphatic ketones the reaction is generally limited to condensation leading to a(N) coordinated bis-hydrazone compounds of type II. A structural and dynamic study of these latter compounds was undertaken in connection with the mechanism of metallation.

The low-temperature _H_nmr__sp_ectra of compound Ila, trans-PdCl~ [0NMe-N»CMe2]2, exhibits an important downfield shift for one of the methyl signals, which was traced to the effect of the anisotropy of palladium and affords evidence for a strong PcL.CH. interaction with one of the ketonic residues, resulting in the non-equivalence of the two ligands. The variable-temperature nmr data showed that these two ligands exchange roles rapidly and that there is an alternation in the Pd-CH interaction. This exchange is intramolecular, and a concerted oscillation of the two ligands about the Pd-N bonds is tentatively proposed as the most probable exchange process. The preferential inter- action of the metal with the ketonic residue of the hydrazone ligand leads to cyclo- metallation in favorable cases.

Further investigations of hydrazone complexes of palladium(II) (hydrazone •

0NH-N*CMe2, ptolNH-N»CMe2> 0NMe-N-CHMe and 0NH-N»CHMe) were made in order to ascer- tain the influence of the»electronic distribution in the Nt"^ group on these metal alkyl interactions.

Cl I—Ar

II III.a.33 207

SITION METAL DERIVATIVES OF BIS-TRIMETHYLSILYIAMIDE AND DI-ISOPROPYIAMIDE LIGANDS o/Claudio Airoldi, Donald C. Bradley and Halina Chudzynska

Department of Chemistry, Queen Mary Colleger Mile End Road, London El 4NS. U.K.

The use. of bulky ligands [L * NPr2 or N(SiMe3)£] has led to the isolation of

unusually low-coordinated complexes of .transition metals, lanthanides and actinides

JD.C. Bradley, Chem. Britain, 11_, 393 (1975)]. Earlier work showed that substitution

of ThC£i, by LiN(SiMe3)2 was restricted by steric hindrance to the formation of

ThC£(N(SiMe3)2j3 [D.C. Bradley, J.S. Ghotra and F.A. Hart, Inorg.Nucl.Chem.Letters,

10, 209 (1974)] and a preliminary report [claudio Airoldi and D.C. Bradley, Inorg.

Nucl.Chem.Letters, U, 155 (1975)] showed that TiCA.., behaved similarly. In this

paper we report the results of variable temperature n.m.r. studies on the monochlorides

which show that the titanium compound is a fluctional molecule due to hindered

rotation of the silylamide ligands. Results of reactions of ZrCi^, N0CJI5 and TaC*5

with LiNPrl and LiN(SiMe3)2 will be reported together with some results on the

corresponding reactions of VOC&3, NbOCi.3 'and TaOC&3. A series of pseudo-tetrahedral

molecules JML3L*J—has now been established:- (a) M = Cr, L - NPr£ or N(SiMe3)2»

L* «= NO; (b)(M = La, \ = N(SiMe3)2, L' =M>(C6H5)3; (c) M = Ti, L = NPr2 or N(SiMe3>2#

L' = C&; M = Th, L * N(SiMe3)2, L" = Cl; (d) M - Nb or Ta, L = N(SiMe3)2, L' •= O.

j 208 III.a.R.5

THE STRUCTURE STUDIES ON Pd/ll/ Mb Cu/Il/ DIPEPTIDE COMPLEXES VTTH THE MAGNETIC RESONANCE METHODS Boguslawa JEZOWSKA-TRZEBIATOWSKA and Henryk KOZLOWSKI Institute of Chemistry,University of Wroolaw,Wroclaw POLAND The NMR studies of 1:1 Pd/ll/ complexes with Glycil-L-Aspa- rtio Acid/Gly-Asp/ and Gly-Tyr have shown that both ligands a- re tridentate within the 3 to 12 pH region. A conformation of the ligands are found to be a similar with noncoordinated bul- ky groups p-carboxy in Gly Asp and aromatic ring in Gly Tyr over the complex plane. The hydrolysis of a metal carboxy1 bond leads to the symmetry lowering and spectrum of glycine residue is of AB type.The values of the £*)) ^ increase in the series: Gly Gly/OHz/,Gly Asp/24.5 Hz/,Gly Glu /37.7 Hz/ and Gly Tyr /kZ.6 Hz/. The similar phenomenon has been observed for" the Cu/ll/ complexes with mentioned above dipeptides. The EPR spe- ctra are of the axial symmetry for pH region up to 12 and of the orthorhorabic one for the higher pH region. Th« symmetry de- crease are alao caused by the double hydrolysis of the Metal ion. The & s { g - g values are increasing in the series: Gly Gly/O/, Gly A.sp/0.1/, Gly Glu/0.11?/, Gly Tyr/O.iV*

In the sane order the A(| increases and gt| deoreases. The Ay1 ^n and -A _, values are both inoreasing with the bulk of the dipeptide side-ohain. The side chain influence through the aaide nitrogen seeas to be the responsible tor the syaaetry lo- wering in both aetal ion ooaplexes. The side ohain may oause that if the ligand is bidentate, the ohelate ring is not larger planar but sore siailar to the ethy- le»ediaaine one. In Such oase the AB type of glyoine atethyleae protons oould be expeoted. 9/1 III.a.34 209 Uetal halide complexes of [JJÎS (1-cnloro, 1- phenyl imina) /A dichloro phosphonium] phospnorus hexacnloride (I) . 7 ^/PRELIMIN Karco Schwartz M Alexis settle Z.. Fac. iigronomîa Inst. Ciencias L. de Ciiile, Sta. ,\osa U. Católica de Chile Parad. 32 1/2 Vicuna i'.ackenna 4860 La Gran j a. Santiago-Chile ijantiago-Chile

A number of addition compounds involving linear (L. F. 2-iorâu, J. Inorg. ^ucl. Caeiu., 3_0, 1405, (1968)) and ciclic phosuuaaenes (21. r. Lai-pert, G. Srivastava, J. Chem. boc. (A) , 210, (196Û)) iiave been report.?.u. We nave stuuied tne interac- tion uetween soi.ie ^ev.is acius v.'itn a linear organic phospha- zene.

The reaction between I and aluminium trichloride in 1,2 dichoroethane, unuer controlled conditions yieldeu an oily brownish material, on tvaporatiny tne solvent brillant and + transparent crystals of tne coii.pounc (ph-C(Cl)=W^"2PCl2 AlCl. were obtained. 31 The ^ P_nn,r__aj-.ectruiu siic./ed a sharp singlet at o = -39.8 pprc wnich xs assined to a tetracoordinatea phosphorus atorû, the fact also is suggesting that the positive charge on the cation is essentially concentrated over the r atom. Ä similar shift was ouscrvea for the, cation in the phos- phazene I. ïhe coiupounu II is more stable than the complex I, but equally hyaroscopie.

Analogous results were achieved from the reaction bet- ween I ana TiCl., using benzene as the solvent, obtaining apart of the phosphazene (III) a yellow solid that seems to oe the complex salt [PCI4] [ï^Clg] (T. J. Kisteniuacher, G. D. Stucky, Inorg. Chem. i£, 122, (1971)). 31 1 Based on the IK, P nmr and H nmr spectra the struc- ture of the above mentioned complexes are suggested. 210 III.a.36

Ln(PF6), . 4TDTD . 4H20 (Ln • La-Lu, Y; TDTD - 1,4 - dithiane - 1,4 - dioxide) as very fine powders. Recrystal1ized single crystals are always complexly twinned and show the same D-S powder pattern as the original powders. Precession, Weissenberg and rotation methods were used to determine the crystallographic characteristics of the compounds with Ln-La, Ce, Yb. The La and Ce compounds are monoclinic with $' close to 90° and P2, Pm, P2/m as possible space groups (difraction symbol is 2/mP ...)• The Yb compound shows orthorhombic symmetry, space group Pnca (Pbcn is the standard orientation). Dou- bling of two axes increases the unit cell content from 1 in the monoclinic to 4 in the orthorhombic crystals. D-S powder films were made of all the recrystal1ized material (Cr Ka, Si as internal standard) and a few lines computer-indexed. Cell constants were calculated using conventional least-squares computer methods. All complexes with Ln»Y , La to Tm, have comparable powder patterns and are thus monoclinic, while the Lu pattern is identical to that of the orthorhombic Yb. Cell parameters, chage from a « 9,05(1) , b - 9.12(2), c - 12.44(1) A, V « 1026(2) A3 (Y compound) to a - 8.93(1), b - 9.31(2) , c - 12.41(2)A, V - 1031.(2) A3 (Tm compound) while 6 changes from 92°06'(6) to 91°51'(10); corresponding data for the Yb compound are 17.19(4), 17.75(3), 13.37(2) A, V * 1020(3) A (V per molecule). There is, within the low resolution of the cell para- meters, an irregular tendency for the cell parameters to decrease, probably controlled by a small overall lanthanide contraction effect (Siekierski, J.. Inorg. Nucl. Chem.,33. 377, (197D).

* Supported by FAPESP A III.a.36 211

THE STRUCTURE OF TERPYRIDIN-COMPLEXES nH20 \ [M11: NI2+, CU2+, LOW-SPIN C02+] - THE STERIC INFLUENCE of THE JAHN-TELLER EFFECT D.Reinen, W.Henke and R.Allmann Department of Chemistry University of Marburg BRD

The rigid frame work of the tridentate terpyridin ligand imposes a distorted octahedral coordination on the M -transition-metal ion in compounds n M (terpy),X9 nH9O [X = Cl", Br", NO~, C107]» which is a tetragonal 112+ compression along z (fig.)- If M is Cu with a highly Jahn-Teller unstable 2E -groundstate however, a tetragonal elongation is additionally active in the x-direction perpendicular to z (fig.), leading to an o-rhombic coordination in first approximation (table). The cooperative Jahn-Teller ordering of the 2+ r

Cu(terpy)2 -ions in the unit cell is antiferrodistortive. Depending on the nature of the x"-anions and the number of H20 in the unit cell a phase tran- sition to a planar dynamic structure may occur at higher temperatures, in which the differing M -N bond lengths in the plane iz equilibrate in time averagEvidence e (fig.)for simila. Singlr eeffect crystal_X-ras in complexev ands EPR-datwith low-spin-Ca will beo 2presente+ will db e(table) given . in addition. table Cu-N bond lengths, N-Cu-N bond angles and figure

g-values in Cu(terpy)2(N03)2 [298K data]

1,96 5* (+z) (+z) - Cu - (-Z) 180° 0 2,01 A (-z) (+z) - Cu -<±x) 79° 0 2,085A <*x) (+z) - Cu -C-y) 104° 0 2,29 A

9x = 2, 258 gv = 2,09g g, = 22,03?

g-values for Cu(terpy)2(C104)2 2H20 298K 4,2K Tw-

gx 2,25, 2,10j

2.031 2,04, V electronic spectra and cyclic voltammetry data,

i A. &0 III.a.R.6 v I Structure of di-y-ch loro-af-dichVoro (2,2'-sulfinyldiethanol) dipalladium (II) [PdCl2.sde|2 L. M. M. de Matheus , H .Horiuchi2, Marcos H.Hatada, N.Aikawa3, E.Giesbrecht. Institute de Quimica, Universidade de Sao Paulo. 1 - Departamento de Quimica, Universidad Nacional de Colombia. 2 - Present address: Dept.of Materials Sciences, Mass.Inst.of Tech. 3 - Dept. of Geosciences, Osaka City University.

The structure of the compound represented by the minimum

formula |PdCl2-sde|2 was determined by X-ray diffraction.

The crystal is orthorhombic and belongs to the space

group Pbca containing four molecules in the unit cell with

a - 10.8337 8 , b = 19.1821 2 and c = 8.9061 8. The diffraction

data were corrected for Lorentz and polarization effects an a total

of 1647 reflections were used (no correction for absorption effects

was made). The crystal structure was determined by the heavy atom

method. The coordinates of the palladium atom were obtained from

the Patterson synthesis, together with sulfur and chlorine atoms.

An electron density map was calculated and the positions of the

oxygen and carbon atoms were obtained. Better atomic posiffions were

determined by using a least squares refinement with isotropic and

later anisotropic thermal factors.

The main non-refined atomic distances and angles are

shown in the table: Pd - Pd 3.47 8 Cl1 Pd - Cl 1 86° Pd - Cl1 2.36 8 S Pd - Cl2 87° Pd - Cl2 2.33 8 Pd S - 0 109° 1 Pd - S 2.22 A Pd S - c 103° 2 S - 0 1.47 8 Pd S - c 58° '2'3 '"4'2 as a consquence of very pronounced ability of uranyl ion to form coordination complexes.

III.a.37 213

STRUCTURAL INVESTIGATIONS OF METAL t-BUTOXIDES AND RELATED COMPOUNDS '\ o/x-i E. Weiss and Th. Greiser Inatitut fur Anorganiache und Angevandte Chemie der Universitat Hamburg, Martin-Luther-King-Plata: 6, D-2000 Hamburg, Germany In contrast to alkali methoxides which have layer structures in the solid state I alkoxidea with bulky substituents tend to form cligoaeric associates. Thus the t-butoxides ' as veil as the trimethylsilanolates ' of K, Rb and Cs have been shovn to possess cubane type structures (Fig l). Recently ve have found that Na-t-butoxide in the solid state exists as hexaaeric and nonaaeric associates in the ratio 1:1 (Fig.2). The nonaaer represents a new type of structure. Oligomers exists also in the gas phase as shovn by mass spectrometry. Cu(l)-t-butoxide is tetrameric but contains an almost planar ring of Cu and 0 atoas(Fig 3).

(1) E. Weiss et al., Z. anorg. allg. Chem. JJ32 (1964) 197 and 2Zg (1976) 206; Helv. chim. acta XVIII (1963) 2051. (2) E. Weiss, H. Alsdorf and H.-F. Griitzmacher, Chem.Ber. 101 (1968) 3770. . (3) E. Weiss, K. Hoffmann and H.-F. Grutzmachcr, Chem.Ber. 103. (1970) 1190.

M«3C-

O SiurC O CH3 Pig. 1: (t-BuOK)1; Fig. 3

Fig.2 (t-BuONa)9 and (t-BuONa)6 •.torn causing the acido-ligand transfer into the equatorial plane of the octahedron, while one of the cis-fluorine atoms transfer in trans- position to the multiple-bonded ligand (or OR-group).

214 III.a.38

RAY DIFFRACTION STUDIES ON THE STRUCTURES OF AQUA- AND AMMINE-COMPLEXES OF METAL IONS IN SOLUTION

H. Ohtaki, T. Yamaguchi and M. Maeda

Department of Electronic Chemistry, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152 (JAPAN)

The structures of aqua- and ammine-complexes of some metal ions have been determined by means of X-ray diffraction of solutions containing relevant metal complexes. The concentrations of each complex were about

2-3 mol dm" and the Table 1. Tiie ou^uctures of Aqua- and Ammine-Complexes of Metal Ions and the measurements were carried Metal-Ligand Distances*. out at 25°C on an X-ray Ion Complex 1 L/10 cm Ref diffractometer for liq- + + Na Na(H2O)4 (tet) 2.4 1 f\ 1 2+ 2+ uids (JEOL, Tokyo). From Mn Mn(H2O)6 (oct) 2.20 2 2+ Fe(H O) 2+ (oct) the radial distribution 2 6 2.12 2 2+ 2 Co Co(H20)6 + (oct) 2.08 2 O 1 curves of the solutions, 2+ 2+ Ni Ni(H2O)6 (oct) 2,.04 2 2+ 2+ the interatomic distance Cu Cu(H2O)6 (dis.oct) 1,.94,2.43 3 CU(NH ) (H 2+ and the number of ligand 3 4 2O)2 (dis.oct) 2.,04,2.33 4 2+ 2+ atoms coordinated to a Zn Zn(H2O)g (oct) 2.,08 2 Zn(NH ) 2+ metal ion were determined. 3 4 (tet) 2.02 4 + Ag Ag(H2O)2+ din) 2.45 5 In some cases the results + Ag(NH3)2 din) 2.22 5 2+ 2+ were refined by the least Cd Cd(H2O)6 (oct) 2.31 6 3+ ln In(H2O)63+ (oct) squares method for the 2.15 7 I)M> inf(in<.itv dat, The struc- Maeda, H. Ohtaki, Bull Chem. Soc. Japan, intensity data. The struc £8,3755. (1975); 2)H. Ohtaki, T. Yamaguchi, M. , Maeda, ibid, tures and. the interatomic Maeaa iulT. < 4 T j- *. „ « K«+.,^O« 4-v,= «-„ ) * Yamaguchi, H. Ohtaki, to be published; distances between the cen- 5)M> Maeda^ y> Maegawa, H. Ohtaki, to be 4. T «*. i» =«/) n^=,r,^ • published; 6)H. Ohtaki, M. Maeda, S. Ito, Bull, tral metals and ligand chem. Soc. Japan, 47, 2217 (1974); 7)M. Maeda, atoms are summarized in *' oht^ki' t0 be published. * lin=linear, tet=tetrahedral, oct=octahedral, Table 1. dis.oct=distorted octahedral structures. we proposed reaction mechanism. The tempera obs will be presented. Acknowledgment^ Financial support from the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo and from the Conselho Nacional de Pesguisas is •cknowledged.

III.a.39 215

X-RAY STRUCTURE DETERMINATION AND SOME PROPERTIES OF AQUOHEXAKIS(1,3-DI- METHYLUREA)£RBJJJ£(III) PERCHLORATE.AN UNUSUAL CASE OF HEPTACOORDINATION. E.GIesbrecht, M.C.Mattos* E.Surcouf^J-P, Mornon*1ind M.K.Kuya Instituto de QuTmica, Universidade de Sao Paulo Caixa Postal 20780 - Sao Paulo, Brazil

The title compound was synthesized and characterized by elemental analysis, infrared spectra, conductance and molecular weight measurements. The crystalline structure of the compound has been determined by X-ray diffraction. Crystals are monoclinic, space group C2/c, with a = 20.13, b = 9.90, c = 21.31 8, 3 = 108.2°, d(obsd.) = 1.65, d(calcd.) = 1.67 for Z = 4. is coordinated to 6 0 atoms of the dimethylurea groups and to the water molecule. The polyhedron can be described as a distorted pentagonal bipyramid; this polyhedron has

rigorously C2 symmetry. The erbium and the water molecule lie on the binary axis. This is the first example of heptacoordination with Cg symmetry, a model which has been theoretically proposed (T.A.Claxton and G.C.Benson, Can. J. Chem., 44, 157 (1966)). The average distance Er-0 (dmu) is 2.25 X and Er-0 (water) is 2.40 8.

The bound water molecule was also confirmed by Karl Fischer titration and thermogravimetric analysis. The corresponding anhydrous compound can be easily obtained by dehydration in vaeuo over P^-IQ °>* heating the aquated species at 100°C. has fai bridgin Mn(VII) lengths Comissao Nacional de Energia Nuclear, DIN. Mn(VII) R. General Severiano, 90, Rio de Janeiro, BRAZIL. Mn(VII) ** Laboratoire de Mineralogie-Cristallographie the pos! Universite P. et M. Curie, T.16. ting the 4, place Jussieu. 75230 Paris Cedex 05. FRANCE parts oi correlat Mn in tl the Mn(\ 216 6 III.a.40

STRUCTURE AND BONDING IN MANGANESE(IV,VII) COMPOUNDS: CRYSTAL STRUCTURE

STUDIES ON DIFFERENT PHASES CONTAINING THE [Mn(MnO4)g] " ION B. Krebs, K.D. Hasse and D. Fischer Faculty of Chemistry, University of Bielefeld, P.O. Box 8640, Bielefeld, Germany (Federal Republic) Attempts to prepare solid permanganic acid have not lead so far to con- clusive evidence on the existence of solid phases in the system Mn2O7 - + H2O such as HMnO4, HMnO4.nH2O, Mn2O7.nH2O, or H.jO MnO4~ (a: N.A. Frigerio, J. Amer. Chem. Soc. 9JL» 6200 (1969); b: B. Krebs andK.D. Hasse, Z. Natur- forsch. 28b, 218 (1973) ; c: B. Krebs and K.D. Hasse, Angew. Chem. int. Ed. V3_, 603 (1974)). Low-temperature distillation experiments (-45°C, 10 torr) on aqueous solutions of pure permanganic acid, together with spectral and analytical evidence, indicate that the solid product consists of Mn2O7, or mixtures of the oxide with ice. If the evaporation is done between -10° and -40 C, evolution of oxygen from thermal decomposition of the cone, so- lutions results in partial reduction of Mn(VII) (see ref. cabove). Pure crystalline solid phases are obtained, containing the dianion [Mn(MnO4)6],2- as a new type of heteropoly-anion and as the first known Mn(lV,Vll) compound. Three different phases with compositions (H-O) 2JjMn (MnO4) g]. 11H2O (p Fdd2, a = 17.778, b = 64.172, c = 10.3908, Z = 16; Ip a = 17.75, b =

31.20, c = 10.36 8, Z =8) and (H3O) 2[Mn (MnO4)g]. 5H2O (III: PT, a = 10.072, b = 8.042,/c= 14.838 8,« = 91.75, 0 = 93.87, J» = 99.56°, Z=2, allat-120°C) were isolated; single crystal X-ray structure analyses were done at -120°C. Present R values are 5.5% (I) and 5.8% (irr) . The central Mn(IV) has fairly regular octahedral oxygen coordination, the six 0 atoms being bridging corners to the Mn(VII)0. tetrahedra. The arrangement of the Mn(VII) atoms relative to the Mn(IV) is trigonal prismatic. Mean bond lengths are: Mn(IV)-O: p 1.883 (1.853... 1. 917) , III: 1.886 (1.849.. .1.926);

Mn(VII)-Obrid : I: 1.710 (1.670...1.739) , lip 1.714 (1.690...1.732);

Mn(VII)-Oterm :p 1.586 (1.541... 1.617) , lip 1.582 (1.534. .. 1.603 (6))S, the possibly significant differences for the 5- and 11-hydrates indica- ting the influence of the strongly hydrogen-bonded cation and water parts of the structures. The structural and spectral data can be well correlated to those of other Mn(IV) and Mn(VII) compounds. The central Mn in the heptameric anion can be replaced by other quadrivalent atoms, the Mn(VII) in the ligand tetrahedra by Tc(VII) and Re(VII). III.a.41 217 COORDINATION STOICHEIOMETRY OF SOME POLYNUCLEAR COMPLEXES OF COPPER(II) FROM THEIR K-EDGE ABSORPTION SPECTRA H.L. Nigam, J. Prasad and V. Krishna Department of Chemistry, University of Allahabad, 211002, India (* Present Address - Department of Chemistry, Univ.of Indore,Indore-l,India X-ray absorption spectroscopy has been used for investigating many problems of structural-chemical importance, particularly in the field of coordination compounds (R.L.Barinsky, Zhur.Strukt.Khim 8_, 897,(1967). However, a very important feature of these spectra, viz. the edge-width has not been sufficiently exploited. Keeling has defined edgewidth as the difference in energy between the inflexion point and the main absorption maximum of the edge (R.O.Keeling Junior, Developments inapplied spectroscopy, Plenum Press, New York 2_,263, (1963) . The edgewidth has been shown to be intimately related with the coordination stoicheiometry which is defined as the sum of the individual nearest neighbours - electronegativity difference for all atoms in the coordination sphere(H.L.Nigam and U.C.Srivastava, Chem.Comm.761,(1971). This relashionship has been exploited in the present investigation to study the coordination symmetry of some of the polynuclear complexes of copper(II) involving ligands like 3,4,5, pyradazine trithiol, 1,3,4, thiadiazole-2,5,dithiol,Quinazoline (1H 3H)-2,4-dithione, l,phenyl tetra- zoline -5-thione which are known to give complexes with polymeric nature and in some cases also with semiconducting behaviour. The eeerdination symmetry of some dimeric copper carboxylates and -halocomplexes as verified by this method has been compared with the crystallographic observations on these complexes. The edgewidth for tetrahedral sites is known to be greater than for those having the metal ion in octahedral sites. A generalisation of this concept has been attempted by studying the copper complexes involving similar ligands but by changing the coo£ dination symmetry. A few more complexes of copper (II) involving li- gands like thiopropionic acid, thiosalicylic acid, thiomalic acid have been studied. 218 III.a.41 THE COORDINATION POLYMERS MB(CN).T . K.E.Bessler ' Department of Chemistry, University of Brasilia dia 70.000 Brasilia D.F. Brazil The new crystalline and isomorphous compounds AgB(CN)^ and CuB(CN). were obtained by reaction of silver cyanide or copper cyanide with boron trichloride at 150 or 220°C re- spectively. The X-ray diffraction pattern (powder) of both compounds can be attributed to a cubic structure (space group 0, ) with 8 formula units per elementary cell. The cell constants are a = 11.3 and 10.7 A respectively. The metal and the boron atoms are tetrahedrically coordinated n by the cyanide group with the distances d B-CN-Ag =4.89 and d B-CN-Cu = 4.63 A. The compounds are stable at ordinary conditions and resistant against acids and bases. They are completely insoluble and decompose at about 35O°C without fusion, liberating cyanogen. Attempts to prepare the corresponding gold compound were unsuccessful. a- re

>r temperatures. The JAg-P values for the cationic complexes are very similar but the JAg-P values for the molecular complexes show a marked dependence upon X. The for- mation of two or three-coordinate non-labile silver-phosphine complexes in the present work can be attributed to the large steric requirement of Bu,P. ., ••VtfJ'

III.a.R.7 219

STRUCTURE AND BONDING IN TRANSITION METAL COMPOUNDS MHMEIVF,

D.Reinen and F.Steffens

Department of Chemistry University of Marburg BRD

H IV 11 2+ 2+ IV Compounds M Me F6 [M : Cr - Zn Me : Ge - Pb ; Ti -JJfJ crystallise in

the ordered ReO,-structure (Ou or T. ;' I) and in the hexagonanal LLiSbFi c-structure II IV (II) respectively, with octahedrally coordinated M - and Me -ions. We have studied the phase-transitions of these fluorides from II to I in dependence on the temperature. The low-temperature modification II with M - F - Me bond angles, which deviate appreciably from 180°, is stabilised with respect to I, II IV if the number of d-electrons in the valence shell of M and Me is large and if M and Me are relatively small. The M - F bond properties will be dis- cussed on the basis of the ligand-field and X-ray data. In case of M -ions with a Jahn-Teller unstable 2E -groundstate (Cu , Cr ) a tetragonal low-temperature

modification with c/a < 1 (III) is observed in addition. CuHf(Zr)Fg for example show phase transitions from III to II at 50(80)K and from II to I at 160(95)K. Structural and EPR-data for the Jahn-Teller modification III will be presented.

\. Me \ II

1 (/ III.b.38 220

| INVESTIGATION OP THE STRUCTURE AND STEREOCHEMISTRY OF COORDINATION Complexir COMPOUNDS IN MOI/FSN SALTS BY ELECTRONIC A1\TD VIBRATIONAL SPECTROSCOPY S.V. Volkov^and K.B. Yatsimirsky P. Lenarc x Institute of General and Inorganic Chemistry , UkrSSR Academy of Institute Sciences, Kiev, USSR The spectral characteristics, electronic structure parameters and stereochemistry of the coordination compounds of 3d metal ions in The comp] molten chlorides, , nitrates and sulphates of alkali metals tigated: in the temperature range of 150 to 900°C and frequency range of 40000 1-phenyl- —1 to 50 cm of d-d electronic, Raman and infrared spectra are discussed. dimethylp Maximally coordinately saturated inner-sphere nitrato and sulphato lution, £ complexes of 3d metals have been detected for the first time. of cardie The important role of <5 - (isocyanate complexes), 6- and 1K- been show (chloride, nitrate, sulphate complexes) modes of interaction (apart stants of from ion-ion interaction) in complexes in melts is demonstrated. /II/. F The stereochemistry of thiocyanate, nitrate and sulphate complexes has nation sp been determined as a function of ambidentity and dentatity, which vary sxpected in the series of 3d metal complexes, ligands. nation b The problem (highly specific to such systems) is discussed of the s been effect of outers-sphere cations, which lie right in the second coordi- ihotomet nation sphere of the complex and influence its structure, thermodynamic jlexes. and kinetic properties. u/ll/. These and other questions are discussed in detail in the monograph the rema' "Spektroskopiya rasplavlennykh sole! (spectroscopy of molten salts) to form by S.V. Volkov and K.B. Yatsimirsky, 1977* Naukova Dumka Publishers, The stab" Kiev, DSSB. their st nd Zn/II ized at ied by th lation of xygen an ine /A/ ined and ave show plexes th •—v.

III. b. 39 C1 (• 221

Complexina properties of azole drugs in aqueous solutions.

U. Lenarcik, M. ./isniewski and M. Gabryszewski Institute of Chemistry, Pedagogical University, 25-020 Kielce, Poland

The completing properties of some druos ivith azole rings have been inves- tigated: pentamethylenetetrazolc /I/, l-mcthyl-2-mcrcLiptoimidazole /2/, l-phenyl-2,3-dimethyl-4-dimethylaminopyrazol-5-on2 /3/ and l-phenyl-2,3- dimethylpyrazol-5-one /»!•/. The measurements have been made in aqueous so- lution, at a constant ionic strength 0,5 /!

stants of ML complexes have been determined and of MLp complex with Zu/11/. Probably, /I/ substitutes only one water molecule in th; co-ordi- lation sphere of the metal. Accordingly, two silver/I/ compounds may be sxpected, since its co-ordination number is usually two. The complex for- nation between thiamazola /Z/ .and Cu/II/, 2n/II/, Pd/II/, Ag/I/ and Cd/II, las been studied by using the potentiometric method. Moreover the spectro- shotometric method has been used for studying the Cu/II/ and Pd/II/ com- Dlexes. Of the compounds studied the most stable are those formed by :u/II/, Pd/II/ and Ag/I/. The Zn/II/ and Cd/II/ complexes differ from the remaining ones by a very low stability. Pyramidon /3/ has been found to form co-ordination compounds with Co/11/, Ml/11/, Cu/II/, and Zn/II/. The stability constants of the complexes have been determined as well as their structure. It has been found that in the case of Co/II/, Ni/II/, and Zn/II/, /3/ form complexes only through the lone electron pair loca- Lized at the nitrogen atom or at the oxygen one. An exception is provi- ied by the Cu/II/ complexes which show enhanced as being due to the for- nation of chelate compounds in which the lone electron pairs at both the ixygen and nitrogen atoms are engaged. The stability constants of antipy- •ine /A/ complexes of Mn/II/, Cu/II/, Zn/II/ and Cd/II/ have been deter- nined and their structures have been discussed. Results of measurements lave shown that Cu/II/ and Cd/II/ form with studied drug more stable com- plexes than Mn/II/ and Zn/II/. 222 III.b.40 6TABILIT THERMODYNAMICS OF COPPER(II) COMPLEXES OF SOME DICARBOXYLIC ACIDS Helmut S CONTAINING ELEMENTS OF GROUP 6B Institut R. Call, E. Rj.zzarelli. S. Sanunartano and G. Siracusa jSpitalst Istituto di Chimica Generale, Universita di Catania, v. A. Doria 8, j "Sof 95125 - Catania (Italy) the "sof jmetal io Recently we have investigated the equilibria of the copper(II) ion reasons with iminodiacetic or dipicolinic acids (R. Call, S. Musumeci, E. Riz, it is kn zarelli and S. Sammartano, Proc. IX National Meeting of Inorganic able to Chemistry, A.I.e.I., (Nerano) E7 (1976)). The structure of the coordi Cu2+ (H. nation compounds was inferred from ^H and AS changes. The different Biochemi coordination features were thought to be due to a difference in rig^L ally, d^ group. Ti dity of the ligand molecule. studied - Now we report here the thermodynamic studies of complexation of co£ wissensc] per(II) ion with the ligands X(R-COOH) (X = O,S,Se and R = -CH - or 2 (I = 0.1 -CH -CH -) in aqueous solution at 25 °C and I = 0.1 M (NaNO ) . run (e = . On the basis of NMR measurements (K.B. Dillon and F.J.C. Rossotti, jconstant J.C.S. Dalton, 1005 (1973)), it was proposed that the diglycollate jus ing in< behaves as bidentate ligand with one free carboxylate group. The^|H and AS values that we have found, on the contrary indicate that all with Tht the ligands here reported to behave as tridentate in the 1:1 uncha£ (have Iit1 Cu2+ sys1 ged complexes. the thioe Particularly, by comparing AS values of Cu-succinate system UJS=21.1 of other e.u.), previously reported (G. Arena, R. Call, S. Musumeci, E. Riz For examj zarelli and So Sammartano, La Chimica e l'Industria, 58_, 657(1976)), and log I and Cu-diglycollate system (£S=31.0 e.u.), it is evident that both differenc -COO arms are coordinated in the later complex. possible The AH changes can be rationalized on the basis of the different co as well a valent character of central donor atom of Group 6B. weak, sue as mentio supported TUB* uss 9t III.b. 41 223

STABILITY AND STRUCTURE OF METAL ION-THIOETHER COMPLEXES IN SOLUTION

Helmut Sigel and Volker M. Rheinberger Institute of Inorganic Chemistry, University of Basel, iSpitalstrasse 51, CH-4C56 Basel (Switzerland) + 2+ "Soft" metal ions, like Ag or Hg , form rather stable complexes with the "soft" thioether-sulfur atom, while complex-stability with more "hard" 2+ 2 4* 2 4* metal ions like Mn , Cu , or Zn , is rather low; this is one of the reasons why these latter complexes have hardly been investigated. However it is known that the tetrahydrothiophen sulfur of cl-biotin (vitamin H) is 2+ able to participate in the orientation of divalent cations like Mn or 2+ Cu (H. Sigel et al.. Biochemistry £}, 2687 (1969)/ R. Griesser et al., Biochemistry 22_, 1917 (1973)). Thus these complexes form stereospecific- ally, i.e. the interaction occurs preferentially "trans" to the ureido group. To obtain more insight into the stability of such complexes we studied those of tetrahydrothiophen (Tht) in 50 % aqueous ethanol (Natur- wissenschaften 6>2_, 182 (197 5)) and of 2,2'-thiodiethanol (Tde) in water (I _ 0.1; 25° C). Coordination of Cu to Tde shows an absorption at 330 nm (e = 199 M~ It is therefore possible to determine the stability 2 + jconstant of the Cu -Tde 1:1 complex by the Benesi/ftildebrand method ' -3 iusing increasing amounts of Cu(ClOJ (0.02 to 0.30 M; [Tde] = 5 10 M): Cu 2 X jlog K ,_d x= 0.18 _+ 0.08. This complex is unstable, comparable to that K with Tht (log Cu/rra,t\ = 0.02 _+ 0.04), i.e. the hydroxy groups in Tde have little influence on the complex stability. The advantage of these 2+ 2+ Cu systems is that metal ions like Mn compete for the coordination at the thioether sulfur, and this allows the determination of the stability of other metal ion complexes which by themselves exhibit no absorption. Foanrd examplelog KV^/m, loj g\ ^Jg= 3.(Tde8 +) O.2- -0.2. Thi8 s +metho 0.06,d halosg *JJjJthe advantag(Tde) = -0.2e tha2 t+ smal0.06l, differences in absorption can be measured very exactly, so that it is possible to determine the stability of very weak complexes like Mn(Tde)2+ as well as of rather stable species like Ag(Tde)+. To conclude, although 2+ 2+ weak, such interactions as with Mn or Cu may occur stereospecifically, as mentioned above. The study of further systems is in progress. Supported by the Swiss National Science Foundation. 224 III.b.42

S EXISTENCE OP LARGE SIZE CHELATE RINGS IN METAL(II)ION P0LYAM1NE COMPLEXES. d, i.BarbuQCi.A.Mastroianni

Istituto Chimico,Via Mezzocannone 4»Napoli(Italy)

The polyamine spermidine NH^CHj INHCCH^NH^ is a substance widely, distributed in biological material,and many works appeared on the distribution of this polyamine in human tissues and organs. Its equilibria of protonation and of Copper(II)and Zinc(II)com plex formation have been investigated in aqueous solution(0.1 H NaCl)at 25cC.The equilibrium constants have been integrated with calorimetric data.Some solid complexes of general formula M(aper midine)Xj (M=Cu,Zn,X=Cl,Br,I)have been also isolated. By a view of the date the full ability of the ligand to coordina te the metal ion with its three nitrogen atoms resuits,therefore a complex with two chelate rings of large sizes:one seven membe- red fused with another six membered,is formed.Also in the solid state the complexes don't exhibit free NH^groups. The AH'values show some difficulty is encountered by the sperm! dine in embracing the three coordination sites.The presence of a protonated complex of formula jjf spermidine H] confirms this view. The presence of chelate rings of so large sizes is inusual.(R.Bar bucci and M.Budini,J.C.S. Dalton 1321(1976)). By considering a series of homologous triamines previously by us studied,we can note the stability of complexes mainly depends on the enthalpy contribution whilst the entropy of formation is as lower as larger the size of the chelate ring,and this is a re- flection of the greater loss of entropy by the ligand. 2,251 2,18C 2.10J 2,03, 2.04 i-\\ .V

III.b.43 225

A NEW TECHNIQUE FOR THE DETERMINATION OF STABILITY CONSTANTS AT BOILING TEMPERATURES

Walace A. de Oliveira.

Instituto de Quimica - Universidade Estadual de Campinas C.P. 1170 - Campinas, S.P., Brazil

Measurements of boiling temperatures may be used to follow chemical reactions which occur with a net change in the number of particles present in the system at equilibrium. This is possible because the boiling temperature is a function of the total number of particles in the solution. Stability constants of complex compounds may be determined from this information, in favorable cases. A simplified method of calculation has been developed, and its underlying theory will be discussed. This technique involves the ebulliometric titration of a solution of the metal with a salt of the ligand and allows for the determination of K,, K-... K of complexes at the boiling temperature of the solution. A twin-thermistor ebullioscope useful for the measurements of precise boiling-temperature elevations will be described. This apparatus is simple and inexpensive and yields data with a standard error of about 45 ydeg. Experimental results involving the stability constants for the complexes of CdX. n (X= Cl, Br, I; n= 1,2,... at temperatures around 100 will be presented. Pd - Cl2 2.33 8 Pd - S - 0 109° 1 Pd - S 2.22 8 Pd - S - c 103° 2 S - 0 1.47 8 Pd - S - c 58°

226 III.b.R.4 C SOME THERMODYNAMIC ASPECTS OF THE CHELATE EFFECT, AND THE ROLE OF S. STERIC STRAIN R.D. Hancock and F. Marsicano. National Institute for Metallurgy, 200 Hans Strydom Avenue, Randburg, South Africa. In a previous paper (J.C.S.(Dalton), 1096 (1976)) it was shown that logK., the formation constant for complexes with polyamines forming five-membered rings on coordination, was related to logK.. for formation of the analogous ammonia complexes, by equation (1). n - 1 logK (polyamine) = 1.152.n. logK^NHg) - i + (n - I)log55.5 (1) i = 1 n is the number of nitrogen donor-atoms in the complex, the factor of 1.152 takes into account the inductive effect of the bridging ethylene groups of the chelate ring, and the (n - I)log55.5 term corrects for the asymmetry of the standard reference state. is the logarithm of the ratio of successive constants, i.e. logK - logK, -. , for the unidentate analogue, in this case ammonia. manifests itself as entropy in the unidentate analogue, and is therefore commonly held to be of statistical significance. In the polydentate complexes, however, it manifests itself as a decrease in enthalpy change on complex-formation as successively more rings are added to the complex, and so cannot have the same significance as in the unidentate analogue. in complexes of polydentate ligands is discussed as a manifestation of steric strain energy. It is shown that if is treated as an adjustable parameter, and set equal to 1.176 for six-membered rings rather than 0.50 for five-membered rings in complexes of polyamines, formation constants for the six-membered ring complexes can also be satisfactorily predicted. The inductive effect parameter in (1) was estimated from a linear free energy relationship. An analogous linear enthalpy relationship is used to estimate an inductive effect factor for the enthalpy changes on complex-formation of polyamine complexes. This factor is found to be considerably smaller than that obtained by com puter adjustment to a best fit for the observed data. This is discussed in terms of ligand solvation effects. (J SIO

O CH3 J Fig.3 (t-BuOCu),

Pig.l(t-BuOK)4 CMe,

Fig.2 (t-BuONa)9 and (t-BuONa)6

lets. M III.b.44 227 1/ OH THE COMPOSITION AND STRUCTURE OF HOMO- AND HETERO- POLYNUCLEAR COMPLEXES

H.M.Yakubov Department of Chemistry, Lenin Tadjik State University, Dushanbe 16, U.S.S.R.

1. In the result of the investigations on iron (III) complex formation as well as on heteropolynuclear complex formation while iron (III) and chromium (III) being present in acetic acid-water solutions the oxidation potential and gamma-resonance spectroscopy methods for guantitative and gualitative description of homo- and heteropolynuclear compounds being formed in the solutions were wor- ked out. 2. The data obtained by the above methods as well as by elect- ron spectroscopy and thermometrical titration methods have shown that under the selected conditions of the experiment in the soluti- + ons investigated the compounds of Fe,(CH,C00)g(0H)2 and + FeCr2(CHiCOO)6(OH)2 are formed. 3. On the basis of the experimental data analysis obtained by varions methods an idea was proposed that the structure of three- nuclear hydroxoacetate compound iron (III) being formed in the so- lutions differs from the structure of a compound of the same compo- sition evolved in a crystalline form. However, the electron spect- roscopy method shows that the structure of crystalline heteropoly- nuclear iron (III) and chromium (III) compounds remains unchanged in the solutions. 4. Three-nuclear hydroxoacetate iron (III) complexes in the so- lution seem to have cyclic structure where three metal atoms are bo- und by acetate groups as well as bridges: 0 H and . H 0' I I H H H H H distances between the cen-5)M. Maeda, Y. Maegawa, H. Ohtaki, to be published; 6)H. Ohtaki, M. Maeda, S. Ito, Bull. tral metals and ligand Chem. Soc. Japan, £7, 2217 (1974); 7)M. Maeda, atoms are summarized in H. Ohtaki, to be published. * lin=linear, tet=tetrahedral, oct=octahedral, Table 1. dis.oct=distorted octahedral structures.

tfr: /-

228 ub. V.D.iihavrjutsciienico ^/Department of Chemistry State University GSP £Lev-601 2^2601 USSfi Joordioatioa compounds which contain organic ligands are of both theoretical and practic importance. Amino alcohols are of special interest with regard to presence of two different electron donor atoms, Jhi* give attention to study of preferable mode of the coordination of these ligands. Furthermore some amino alcohols are products of metabolism in living organisms and may become a model of metal ions behaviour in living. •He have prepared coordination compounds of tetravalent titanium with ethanolamin (M2A), di- and triethanolamin (D2A, T2A), tris(oxymethylj. aminomethane and 8-oxyquinoline (HOx). The compounds were obtained by schemes:

2)

42) CHH2+4DM30 =fTi(OCH ) C(CH OH)NH 5) TiCl4+ nHOx = TiOxnGl4_n + nHCl • The compounds were investigated by IB- and PMR-sjpectroscopy and by conductivity and cryoscopy. The compounds of composition TiL X^ where L - amino alcohol residue, and 1 - CiT, N", BOS-, NCSe", SGJ--, were prepared by exchange reactions. Intruding of pseudohalogenide ion into coordination sphere results in additional coordination of amino alcohol via nitrogen atom. In the case of T2A this tend to formation of compounds of composition TiCOC^N X . Another anions, in particular NO" and N03, wire not intruding inner coordination sphere. The main results were published (Koordinatsionnaya Ichimioa (Coord. Chem. inEuss.), g, /

.1. III.b.46 229 TRANSITION METAL COMPLEXES OP DEPROTONATED ^-MERCAPTOBENZOXAZOLE. STUDY OP THE THIOL-THIOKETO FORM EQUILIBRIUM. SYNTHESIS J. DEMAND C.Preti, G.Tosi and P.Zannini Laboratoi i Istituto di Chimica Generale ed Inorganica, University of Modena, 4 rue Bla 41100.Modena (Italy). The condei The ligand 2-mercaptobenzoxazole (mbo) exists as two tau.tomeric con- been invei compounds formairioïrs exibiting thiol-thioire- isomerisnr involving -N=C--8H and -NH-C=S groups in the equilibrium: <1> Pd(Xl

X = I .C-SH R = I

The complexing properties of this ligand with metal ions is the aim The conpo of the present research in order to further our present knowledge in for the s (M.I. BRU the field of the ligands which exibit the above reported thiôl-thione cationic equilibrium. We have investigated the structural aspects of the comple-. (2) Pd(C xes of deprotonated mbo with the metal ións Zn(ll), Cd(ll), Hg(II), Cu(I), Ag(l), Au(l), Ni(ll), Pd(ll), Pt(ll), Co(II), Rh(YFl) and Ir(lII). <3) PdCC The in'frared spectra of the complexes do not display the bands due to the NH group stretching and deforming, clearly indicating the absen- ce of the imino-hydrogen in these derivatives. Furthermore it is worth- where O while examining the fact that the mode of coordination of the ligand The stere< can be distinguished by the analysis of the positions and intensities spectro$c< of the thioamide bands. The shifts of these bands are discussed and al- observedf while the low us to suggest both ÏÏ- and S-coordination. The ligand field parame- The stabi ters are in keeping with the proposed structures confirming the presence the solver

of MSjjN;, and MS3K3 chromophores. In acid medium this ligand coordinates in the form (a) through the nitrogen atom only; when operating in basic medium the anionic ligand (c) bonds via both sulphur and nitrogen with an attack of the sulphur anion and by the coordination of the nitrogen. ting tne innuence or. tne strongly nyarogen- on ca parts of the structures. The structural and spectral data can be well correlated to those of other Mn(IV) and Mn(VII) compounds. The central Mn in the heptameric anion can be replaced by other quadrivalent atoms, the Mn(VII) in the ligand tetrahedra by Tc(VII) and Re(VII).

230 III.b.47

SYNTHESIS AND REACTIVITY OF CYCLOPALLADATED COMPOUNDS. J. DEHAND, M. PFEFFER and M. ZINSIUS Laboratoire de Chimie de Coordination, Universite LOUIS PASTEUR 4 rue Blaise Pascal. 67008 STRASBOURG CEDEX (France)

The condensation reaction of several ketones with some palladium-amine complexes has been investigated. Reaction (1) accounts for the following new cyclopalladated compounds :

(1) Pd(XNH2)2Cl2

PhNR. PhCH. The b R = Ph, Me, H attention the oxidat

K.Schwochau, H.J.Schenk, and E.Koglin Institut für Chemie, Institut 4 Angewandte Physikalische Chemie Kernforschungsanlage Jülich GmbH, D-517o Julien, Germany

O.Greis Chemisches Laboratorium der Universität Freiburg Lehrstuhl für Anorganische Chemie, D-78oo Freiburg i.Br., Germany

The binuclear octahalide complexes of and rheniumjaave received much attention because of their multiple metal to metal bonds, their structural features,and the oxidation states of the central atoms. In contrast to the dinegative dirheniumoctaha- lide anions the isostructural stable chloro-complex of technetium has been claimed to be (1965 not dinegative but trinegative (W.K.Bratton and F.A.Cotton, Inorg.Chem. 9_, 789{197o)). res wl From our experience and in view of the close resemblance in chemistry of technetium and The e] rhenium (K.Schwochau, Angew.Chem. ]&_, 9(1964)) the reported different behaviour of the the bi elements in the binuclear octachloro-complexes is difficult to understand. Therefore we the d= reinvestigated the preparation, composition and properties of octachloro-ditechnetate eharac and -dirhenate-.""' '—~~ 99 compl«

The binuclear technetium complex was prepared by reduction of. TcO4 with H3PO2 The We in hydrochloric acid and the butylammonium salt was precipitated. Since the strong para- fitted magnetic [TcCl } is partially precipitated too, a rigorous purification of the binucleai from c complex salt is absolutely necessary. The composition {p-(C4Hg)4N32JTc Cl ^ could be con- 4.2 firmed by analysis. Magnetic susceptibility measurements in the range of room temperature The sp down to liquid helium temperature proved the technetium complex as well as the rhenium soleno complex to be diamagnetic, clearly indicating an even number of electrons of the central The ne atoms. The same composition of the binuclear complex salts was confirmed by X-ray diffrac (mainl tion, demonstrating the isötypical crystal structure. The compounds crystallize in the the te .monoclinic system with two formulas per unit cell. The space group was found to be This r P2 /c. The lattice constants were determined. The far infrared spectra in the, range of try, o 4oo to 4o cm" show the stretching and bending modes. The doublet splittings of the lead t< stretching modes can be explained by thé distortion of the D symmetry. In the diffuse lation reflectance spectra the strong bands at about 7oo ran may be assigned to.the orbitally changii allowed transitions from the metal-metal bonding orbital 0 to the antibonding M.A.De orbital <ƒ*. ' 232 ([ III.b.R.5 hüN(ll) COMPLEXES WÏÏH TRIDEWTAÏE SCHIPP BASE LIÜANDS- MÖSSBAUEK AND ; SPECÏKUSÜOPi. E. Eaggio-Saitovioh1 Hid H.A. De Paoli2 1-Gentro Braaileiro de Pesquisas fisicas, R. Wenceslau Braz 71» de Janeiro, RJ, Brasil. 2-Inst. für Anorganische Chemie, Universität. Prankfurt, W. Germany. We have studied the Mosu Dauer and electronic spectra of a series of iron(II; complexes with tridentate Uganda, such aa: terpyridine (I) , 2-(2'-pyridylmethyleneaminomethyl)pyridine (II), 2,6-pyrididialbisrae - thylimine (III;, l-( 2' -pyridylmethylsneaminomethyl)-2-aminoethane (IV) and l-(2'-pyriaylmfithy".eneaminomethyl)-2-aiDinopropane (V). These com - pounds, as was pointed out by jr. Krumholz (Inorg. ^hem., 4_, 612 and 757 (1965)), belong to a ciujie class having characteristic spectral featu- res which should be conected with the structure of the complex ion. The electronic spectra were taken at 77 °K, to improve resolution, and the band positions were obtained from a log-normal curve analysis of the data. These spectry. -.-.re discussed by comparison with the known characteristic spectra of the ligands and the spectra of the iron '(II) complexes with analogous bidentate ligands. The Mössbuuer spectra, were obtained at 4.2 and 295 °K and the data fitted with two Lorentzian computed curves. The isomer shift varyes from -.ülb to ,10b mm/sec at 295 °K and from -.049 to .058 mm/sec at 4.2 °X, the quadrupole splitting from -1.06 to -.65 mm/sec at 4.2 °K . The spectra obtained with a external magnetic field of a superconductimg solenoid allow us to determine the sign of the quadrupole interaction.

The negative sign for Vzz is maintained along the series of compounds (mainly: I, II, III and IV) in agreement with an early measurement for the terpyridine complex (I)(W.M. Reiff, J.Amer.Chem.Soc.,76,3029(1974)). This result can be understood, for iron(ll) in a Dp^ point group symme- try, on the basis of a strong ©"-bonding along a unique axis, which

lead to an increase in the dz2 orbital population. However, the corre - lation of the Mössbauer parameters suggest that the 1f_back-bondi ng is changing along the series of complexes.

M.A.De Paoli thanks the Humboldt Foundation for a research fellowship. III.b.49 233

ACTIONS OF DINUCLEAR CARBONYL METALLATES(-I) OF THE VI B METALS AND IRON WITH INJDIUMJJLII)-. ( IV) -, AND TIN ( IV) -HALIDES H. Behrens. E. Sixtus, G. Thiele, M. Moll und E. Sepp Institut für Anorganische Chemie der Universität Erlangen-NÜrnberg, D-8520 Erlangen, Bundesrepublik Deutschland

The reactions of disodium decacarbonyl dimetallates(-I) Na,[(OC)5-M-to 1 (CO)5) (M = Cr, Mo, W) with M'X4 (M = Ge, Sn; X = Cl, Br, J) in THF proceed with fission of the M-M bonds to give monomeric complexes of the type M(CO)5M'X,«THF. As has been shown previously, the same compounds are obtained by photochemical reaction of group VI hexacarbonyls with CsGeCl, or SnX„ (X = Cl, Br, J). [H. Behrens and coworkers, Z. Anorg. Allg. Chem. 401, 233 (1973)].

A similar disproportion mechanism is operative in the reactions of Na [M (CO) J (M = Cr, Mo, W) with InX (X = Cl, Br, J) in THF: 2 2 1 0 3 -I i:r Na2(M2

While the complexes M (CO),. InX -THF also exist as monomers in solution, the threefold coordination about the indium atom in Cr(CO)5InBr»THF has been shown by a single crystal X-ray diffraction study to be expanded to a (3+2)-coordination geometry in the solid state by two bromine atoms from adjoining units (In-B.r distances: 264 pm within the Cr(CO) ,-InBr.THF unit, 317,5 and 309,5 pm between units).

Conversely, the iron-iron bond is retained in the reaction of K2 [(OC)4Fe-

Fe(CO)4] with Ph3SnCl or Ph2SnCl2.

Mass, IR, and Raman spectra of the products are fully consistent with their formulation as trans-trans isomers with a linear Sn-Fe-Fe-Sn arrangement (figure).

SnR3 (R3 = PPh3 ,PPh2Cl) •w* h

234 III.b.50

./ORIGINAL POLYMORPHISM OF SOME DINUCLEAR COMPOUNDS OF GENERAL FORMULA^M, M'(SR)0(CO)-'i /(M = Rh(I), M1 = Ir(I)) VERSUS TEMPERATURE, PRESSURE AND COMPOSITION. d~* L * Jean 6ALY and Jean-Jacques BONNET Laboratoire de Chinrie de Coordination du CNRS, BP 4142, 31030 TOULOUSE CEDEX, France

The molecular structures of some dinuclear thioiato bridged coordination compounds of general formula [H2-xMVSRMC0^ where M and M' are resPectively rhodium (I) and indium {I) with x ranging from 0 to 2 and where R is either a phenyl or tertio- butyl group, have been solved using X-ray single crystal techniques. As an example, when R is the tertiobutyl group, the dark [irfSRjfCO^Jj compound crystallizes at room temperature in the hexagonal system with a cell a = 20.83 %,

c = 14.43 A, v = 5475 A , the space group being P6222. When increasing the temperature (T <\, 60°C) that dark hexagonal compound turns red, the new crystalline system being monoclinic with a cell a = 15.95 A, b = 10.33 A, c = 22.22 A, g * 92.1°, v = 3659 A3, the space group being P2. , . The transformation seems to be irreversible. At room tempe- rature and normal pressure, the dark metallic mixed complex of formula DrRn($R)2(C0)4J crystallizes with the hexagonal cell and is isostructural with the dark phase of

|lr(SR)(CO)2l2, while the yellow (Rh(SR)(CO)2"J2 crystallizing in a monoclinic cell is

isostructural with the red phase of flr(SR)(CO)^2. Both phases contain dinuclear units 'with the metal in square planar coordination ("butterfly unit"), organized in different ways ; their crystal chemistry will be discussed in details.

A tentative ternary diagram (including the temperature, the pressure and the composition) is proposed and the discussion of its shape will be enlightened by struc- tural considerations involving particularly the influence of metal-metal interactions through the dihedral angle set up by the two square planar arrangements around each metal and also between the dinuclear units. have shown that Cu/II/ and Cd/II/ form with studied drug more stable com- valent plexes than Mn/II/ and Zn/II/.

III.b.51 235 0 SYNTHESIS, 8 TOWARDS THE ISOLATION OF A 3-COORDINATE d COMPLEX L. J. Bouc Christopher A. Reed and Yohanhes W. Yared Departamer *Departmer Department of Chemistry, University of Southern California New dimeri Los Angeles, California 90007, USA type |Mry Wilkinson's catalyst for the homogeneous hydrogenation of alkenes, RhCl- oxidation (PPh3)3, owes much of its remarkable reactivity to the dissociative formation tetradent; of the intermediate RhCl(PPh3)9, a 3-coordinate d complex. The key position sal icy laic of such a 14-electron compound has been kinetically identified by,the extensive mine, 1,3" rate studies of Hal pern (Cal Tech seminar, 1976) and while 14-electron compounds terized b^ have been isolated and structurally characterized in d systems (e.g. Pd(PPh- I .R. v.v.- (t-Bu),),, S. Otsuka et. al. J. Amer. Chem. Soc., 96, 3322 (1974).) none having tion for 1 8 ~~ 8 I: (SB)Mr a d configuration are known. Both the structural influence of a d configura- tion upon the geometry of a 3-coordinate complex and its anticipated-high chemi- with the c cal reactivity are of interest. planar, 8

Reaction of RhCl(PPh3)3 with TICTO^ in weakly coordinating solvents (ace- magnetic r tone, THF, ROH, RCN) gives high yields of orange or yellow crystalline products dimers she

[Rh(solvent)(PPh3)3]C104. These oxygen sensitive materials are very reactive type I dir towards oxidative addition and substitution reactions providing a convenient even at 7'

synthetic route to RhX(PPh3)3 where X=anion of choice. More interestingly, relaxatior

however, upon recrystallization of the orange salt [Rh(acetone)(PPh3)3]C10^ dinters she from dichloromethane a new red complex is formed. The extreme oxygen sensi- scale. 1\ tivity of this complex and the quantitative reversal to the orange acetone sphere complex upon recrystallization from acetone augurs well for ourtentative form- rigid. p either th« ulation as a 3-coordinate d complex, [Rh(PPh ) ]C10 , but the true nature of 3 3 4 of pseudo this very reactive species awaits an X-ray structural investigation in progress electronic at the time of writing. 1 igand &*i types of < could be r character! se dioxo(c producing

tion,pH<'i. two steps of phenols changes can be rationalized on the basis of the different co valent character of central donor atom of Group 6B. weak, sue as mentio Supported

236 III.b.52

SYNTHESIS, SPECTROSCOPY AND REACTIVITY OF DIMFR^IWITH SCHIFF BASE COMPLEXES OF Mn(lll). STRUCTURE L. J. Boucher, and C. G. Coe* [Rh (O CC Departamento de Quimica, llniversidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. 2 2 M.Moszner *Department of Chemistry, Carnegie-Mellon University, Pittsburgh Pa., U.S.A. New dimeric mixed valence Mn(lll), Mn(lV) complexes and dimeric Mn(lV') complexes of the Institute nave been "\k, Jolio type |Mn2(SB)2(0H)0| and |Mn2(SB)2^)9I prepared by the basic aqueous peroxide oxidation of Mn(III) Schiff base complexes in chloroform or methanol. Here SB is the The new tetradentate Schiff Base derived from the condensation of 4-secbutyisalicylaldehyde, (where K. salicylaldehyde, 4-secbutylhydroxyacetophenone or hydroxyacetophenone with ethyienedia- states) • mine, 1,3-propyIenediamine or {-) 1,2-prooylenediamine. The complexes have been charac- in i^SO^ terized by elemental analysis, solution molecular weights, magnetic moments, ESR, nmr, as well ; I.R. v.v.-visible and CD. spectroscopy. The evidence is consistent with the formula- examined tion for the two types of dimers as: The f olli I: (SB)Mn(l I l)C° IV) (SB} (SB)Mn(lV ) Mn(lV) (SB) b = 8..11' with the octahedrally coordinated metal bound to the tetradentate ligand in the non-co- S meas olanar, 8 configuration, rtoth type 1 and II dimers show reduced room temperature The foun< magnetic moments in the range 2.h to 3.^ B.M. per Mn. The antiferromagnetically coupled shortest dimers show magnetic moments at h°K which are consistent with a S=l/2 ground state for The mean type I dimers and S=*0 for type II. Mo ESR spectra are seen for efther type of dimer distance even at 77°K, indicating that metal-metal interaction gives rise to rapid electron spin can be d< relaxation. The room temperature and variable temperature nmr spectra of both types of dimers show that the non-equivalent orotons are rapidly interconverting on the nmr time with the scale. Thus the metal-metai interaction in the dimers also labilizes the coordination The cataJ sphere of_j:he individual metal atoms and both types of dimers are stereochemically non rigid. ^^Consideration of the shifted resonances of the individual protons indicates either that the mode of electron spin delocalization or that the relative contribution were exan of pseudo contact and contact shifts is different for the two types of dimers. The to be 10- electronic spectra of the dinners are quite similar with ligand IMI , and metal to by the cc ligand

III.b. 53 V " II 237

STRUCTURE AND REACTIVITY OF THE MIXED VALENCE RHODIUM DIMER d jZRySTAL CS M.Moszner, T.Glowiak, and J.J.Ziolkowski S.JEKNNIN, Laboratoir Institute of Chemistry, University of Wroclaw Ik, Joliot-Curie Street, 50-383 Wroclaw, Poland Equips de

The new binuclear complexes of the [Rh2 (OgCR)^ (^0)^010^ type (where K = H, CH^f Cyi^, C^H with rhodium at +2 and +3 oxidation The stu states) were obtained in the reaction of [RhgCOgCRV] with Ce+/* / atons ena in H S0^ medium. The magnetic and spectroscopic properties (UV, VIS, IR) 2 ce on as well as the X-ray structure of [Rh^CH^COO^tHgO^ClO^ were tal-metal cies with examined. The compound crystallized in the triciinic systems Pour canp The following crystallographic data were obtained: a = 8.187(2)1, mercaptoe b = 8.114(2)1, c = 10.120(3)1, oL= 91.85U)?

The catalytic properties of complexes JRh2 (OAc). (H20) JCIOK and The rea JRh2(0Ac)^] in decomposition reaction of the cumene hydroperoxide Ru3H(OO)1 were examined and the reactivity of the first complex was found to be 10 higher than that of the second one. That should be explained by the contribution of the mechanism: Structu a good pr RhCH) ROOH Rh(III) RO' + 0H~ with resu 1 + -* I + by inf rar ROOH RIHII) RO' + H A discuss given. 1 238 III.b.54

\jJ jemawLi CHEMISTRY OF COORDINATION COMPOUNDS IN RELATION WITH CORROSION INHIBITION ' S.JEANNIN, Y.JEANNJN, G.LAVIGNE Laboratoire de Chimie des M€taux de Transition, Universit§ Pierre et Marie Curie 4,Place Jussieu,75230 Paris Cedex 05 Eguipe de Recherche Associee au C.N.R.S. N° 608

The study of the stereochetnical action of organic inhibitors containing sulphur atans enable us to obtain structural models starting from trirutheniutn carbonyl Ru-fCO),-. Then, in order to investigate the influence of the metal-metal distan- ce^on tnS linkage process, we used dinuclear Rg, ftD) which contains a long me- tal-metal bond and from Mn(CO)_Br which is known to easily give polynuclear spe- cies with ligands containing sulphur atoms. Four complexes with mercaptoben2othiazole (Hmbt) have been prepared and one with mercaptoethanoic acid(H_tg); their crystal structures have been solved.

The reaction of Hmbt with Ru^(CO),- results in breakdown of the cluster and for- mation of a dinuclear complex Ru2 (mot)2(CO)g which gives from pyridine recristal- lisation the complex Ru2(mbt)py,fcOK: it is a dinner, with a Ru-Ru bond and two bridging mbt which cooroinate tKrougn the exocyclic sulphur atom and the nitrogen atan; mbt bond lenghts are consistent with a thiolate form. was A mononuclear specie^, Ru(mbt)2py2(GO)T' obtained and reveals that mbt is not bidentate when coordinated to only one metal atom; it is coordinated via the exo- cyclic sulphur atom. Again, mbt is under thiolate form. _ With Mn(CO)5Br and Re2(CO),0, Hmbt leads to isostructural dinuclear LM(mbt)(CO)J. compoundsanpounds; they exhibit a very particular mbt incorporation: both metal atoms are ' joined through a double sulphur bridge and both ligands are also N-bonded, giving unusual four membered Re-S-C-N rings; the complex adopts a boat structure.

The reaction of H_tg with Ru,(CO)l2 keeps the triruthenium cluster. One gets Ru,H(CO)10(Htg) in which H,tg Builds a sulphur bridge between two ruthenium atoms.

Structural results will be discussed in terms of stereochemical arrangement as a good protective action of the two corrosion inhibitors; they will be compared with results that S.Thibault and J.Talbot(Bull.See.Chim.Fr.,1348, (1972)) obtained by infrared multireflections on the inhibited metal surface. , A discussion of the modification of ligand molecule with coordination will be given. com pute discusae

m

L IV. 15 /' 239 V'

COLORFUL COPPER COMPLEX CHEMISTRY "SPECTROPI Erwin Boschmann E. A. New Department of Chemistry, Indiana University-Purdue University at Indianapolis, Indiana, U.S.A. instituti Caixa Po

The talk is based on several year's research on organic analytical reagents for copper. There are literally hundreds of organic reagents for copper Copper(I giving reactions of differing characteristics. Thus, the colors of the products vary from the familiar blues and greens to yellow, red, buff, gray, spectral black, purple, lavender, colorless, to fading colors, chemiluminescence, and brium st flourescence. Some complexes are light sensitive, some are explosive, some are liquids and others are gaseous. The wavelengths used for analytical served a purposes fluctuate between a low 271 to a high 755 nm. Detection and de- The anal; termination limits of 0.00005 micrograms and 10"° %, respectively, have been reported. The methods of detection vary from simple visual color observation tions, a- to photographic and ring oven techniques. Determinations have been carried suits du< out by photometric, radiometric, atomic absorption, nitrometric, reflectance, nephelometric, focusing chromatography, ion selective, heterometric titration, mat ion c< and many other techniques. pH conditions vary from 1 - 14. A discussion of ties. In< the most and the least specific, selective, sensitive, precise, common, etc. reagents will be given on hand of examples. riginal i e t] and 3 factor is found to be considerably smaller than that obtained by com puter adjustment to a best fit for the observed data. This is discussed in terms of ligand solvation effects.

IV. 16 SPECTRO! 3PECTROPHOTOMETRIC AND POTENTIOMETRIC STUDIES OF COPPER(II)-AZIEE COMPLEXES". SYSTEM : L.R.M.P E. A. Neves and E. Oliveira InstitU' Instituto de Qulmica - Universidade de Sao Paulo Caixa P( Caixa Postal 20780, Sao Paulo, Brasil

Copper(II) cations form four successive complexes with azide ions with Previou! spectral characteristics favorable, for analytical purposes and equili- of (p

if) $M IV.17 241 2 SPECTROPUOTOMETRIC STUDIES OF [PdCl4] ~/ETHYLENE-BIS- (THIOGLYCOLIC) ACID SYSTEM IN AQUEOUS SOLUTION.

L.R.M.Pltombo and E.Oliveira

Instituto de Qulmica - Universidade de Sao Paulo Caixa Postal 20780, Sao Paulo, Brasil

Previous spectrophotometrie and condutometric studies on the interaction

of [pdClJ ,~ » and ethylene-bis-(tioglycolic) acid (H2EBTG) showed that two species were formed and the complex compositions 1:1 and 2:1 (ligand- -metal) were found (L.R.M.Pitombo and G.Oliveira Nsto, Anal.Chim.Acta/75, 391, (1975); L.R.M.Pitombo, G.Oliveira Neto and E.Oliveira, Mikrochimica Acta, 1, 61, (1976)).

On the basis of these results and others informations (L.Newman and D.Hu- me, J.Arner.Chem.Soc., 79, 4571, (1957); W.F.Rittner, A.Gulko and G.Schum- ckler, Talanta, 17, 807, (1970)) the following equilibria were investi- gated by spectrophotometry:

2C1 (PdCl4J(aqJ ) H2EBTG(aq) (aq)

K, 2+ + 2C1 (aq) H2EBTG(aq) (aq) (aq)

Consequently it was possible to determine the formation constants (K^ and 2 K2) of the species [pd Cl^EBTG)? . and fpd (H2EBTG)2 } ,*_^ at ionic strenght 3,0M. Tiie compounds obtained are stable in the air. The solubility of in the J compounds in some solvents (JWSt), Ji^A, methanol, ethanol, aceto- medium i nitrile, etc.) was studied qualitatively. an atta!<

242 IV. 18

'Coordination of metal ions by immobilised imidazole ligands 'THE INTERAC J. Reedijk, F.B. Hulsbergen and J.A. Welleman C. Mroldi,

Department of Chemistry, Delft University of Technology, Delft-2208, The Netherlands Institute c plnas, Sao

The coordination of metal ions by imidazole ligands is an important process in nature and technology. During recent years complex formation between metal ions and several in.idazole ligands has been studied extensively and rules concerning stoichiometry and chlorates ( stabilities have been evolved [e.g. R.J. Sundberg and R.B. Martin, Chem. Rev. Jh, dissolve in hi: (197*0). in this non In natural systems, however, imidazole groups occur bound to peptides and proteins chloride, b: which impose certain steric constraints. In catalysis, there is a growing tendency to metric titr; immobilise ligands and complexes, in order to separate products and catalysts. This approach has also been used in the synthesis of ion-exchange resins with functional calorimetri groups as ligands. Host of this work is only qualitative in nature, and no details has jeen pe concerning stoichiometry and structure of the immobilised complexes are known. rized in th Therefore, we have studied the complex formation of imidazole ligands chemically linked to a carrier material. Polystyrene, cross-linked by addition of 2% divinyl benzene, has been selected as a carrier. In the polymer, 10—UOJ? of the phenyl groups has been substituted by -CHg-Imidazole groups. This product is readily swellable in solvents like chloroform. As metal ions Co(ll), Ni(ll), Cu(ll) and Zn(ll) were selected, because the coordina- tion cnemistry of tnese ions with imiaazoles its well known, and because the complex formation can be followed easily with spectroscopic and magnetic techniques. The complexes are synthesized by treating the metal salts as their tf-n-butyl imidazole solvates with the modified polymer in CHC1 . The results allow the following conclusions to be drawn: 1. The polymeric imidazole ligands coordinate similar to monomeric imidazoles, yielding up to six imidazole groups per metal ion, although the ligand-field strength appears to be slightly smaller. This may be due to steric constraints of the polymer. 2. The polyhedra around the metal ions are more or less distorted from ideal, although nearly all imidasole ligands of the resin can be used to coordinate the are esqsected metal ion. interaction 3. Resins of this type can be used to remove traces of metal salts from organic solutions. in the form (a) through the nitrogen atom onlyj when operating in basic medium the anionic ligand (c) bonds via both sulphur and nitrogen with an attack of the sulphur anion and by the coordination of the nitrogen.

•*"

V.5 243

THE INTERACTION BETWEEN SCME LANTHANIDE(III) IONS AND OHIORIDE IN N,N-D2METHYIACETAMrra; THERMODY] C. Mroldi, A. P. Chagas and**?. L. C7~Voipe TIONS AN] Institute de Quimica, Universidade Estadual de Campinas,- Caixa Postal 1170, 13.100 Cam- G. Ander-i pinas, Sao Paulo, Brasil. Laborato: CH-8092 !

The N,N-dimethylacetamide forms stable adducts compounds with lanthanide per- The know! chlorates (T. Moeller and G. Vicentini, J. inorg. nucl. Chen.,27, 1477 (1965)), and they ions woii dissolve in excess of the ligand, providing an excellent medium to study interactions namic da' in this non-aqueouns solvent. Cationic and neutral species between lanthanide(III) and these va'. chloride, bromide and nitrate have been detected by using conductometric and spetrophoto sed conci metric titration (C. Airoldi and G. Vicentini, An. Acad. brasil. Cienc.,44_, 427 (1972)). cations In attempting to obtain more information about this system an incremental Thermodyi caloriroetric titration (J. J. Christensen et. al., Thermochimica Acta, 3, 203-233(1972)) change i: has been performed using a precision LKB 8700-2 calorimeter and the results are summa- reaction rized in the table, where: AS in t] 3+ Ln + el" - cations, LnCl2+ + Cl" = LnCl* ? P all 1:1 of M ca Table - Formation constants and enthalpies of oomplexation cide abo

3+ AH _ T Kl ] K2 AH2 thermod Ln 1 mole.l"1 kJ.mole mole.l" kJ.nole"1 Indeed t La 240 25,8 69 35 aquo ion Ce 260 28,2 35 27 coordina Nd 230 25,0 19 19 edited b Gd 17 -13,1 65 -1,3 In order Er 212 9,9 61 9,8 formatio Yb 175 17,9 13 23 gand was tion of 3+ thermod The enthalpies values change only on the Gd . The endothermic reactions are expected for the hard-hard ions and have been interpreted as mainly electrostatic milar sy interaction between Ln and Cl .

\ -—* ^ ,\\ V

244 V.6

THERMODYNAMICS OF COMPLEX FORMATION BETWEEN TRIVALENT LANTHANIDE^CA- TIONS AND TRIETHYLENETETRAMINEHEXACETATE ION (TTHA) G. Anderegg Laboratorium flir Anorganische Chemie, ETH CH-8092 Zurich, Switzerland. The knowledge of the coordination numbers of trivalent lanthanide aquo ions would be of great help for a detailed discussion of the thermody- namic data of complex formation in solution of these cations. Not only these values are not known, but also different views have been expres- sed concerning their magnitudes within the whole series of lanthanide cations (I. Grenthe and H. Ots, Acta Chem. Scand. 26, 1217 (1972)). Thermodynamic data of complex formation with these cations show that a change in the number of coordinated water molecules set free by this reaction is accompanied by an abrupt change of the^values for AH and AS in the plot of these quantities against the atomic number of the cations. Similar changes have been observed pratically by formation of all 1:1 complexes ML. Because normally the maximum coordination number of M cannot be achieved by the ligand in ML, it is not possible to de- cide about the reason for the particular trend of the values of those thermodynamic quantities plotted as a function of the atomic number. Indeed this can be due to a difference in coordination number of the • aquo ions as well as to a difference in the number of water molecules coordinated to ML ( G. Anderegg in Coordination Chemistry, Volume I, edited by A. E. Martell, Van Nostrand Reinhold, New York, 1971, p. 479). In order to eliminate this ambiguity the investigation of the complex formation of the lanthanide cations with a potentially decadentate li- gand was undertaken. By coordination with this ligand (TTHA) a satura- tion of the coordination sphere of the cation should be achieved. The thermodynamic data of this reaction will be discussed with those of si- milar systems. stretching modes can be explained by the distortion of the D4h symmetry. In the diffuse reflectance spectra the strong bands at about Too n» may be assigned to th. orbit^ly allowed transitions from the metal-metal bonding orbital 6 to the antibonding M.A.De orbital 6*-

-*»

V.7 245

PREDICTION AND MEASUREMENT OF THE FORMATION CONSTANT OF La(Ilty_HITH BIPYRIDYL

R.D. Hancock and A. Evers.

National Institute for Metallurgy, 200 Hans Strydom Avenue, Randburg, South Africa. Formation constants of polydentate ligands of many types have been shown (R.D. Hancock and F. Marsicano, J.C.S.(Dalton), 12, 1096 (1976)) to be related to those of their unidentate analogues by equations such as (1), which relates the formation constants of polyamine ligands (logK.) to log for the analogous ammonia complexes:

j(polyamine) = 1.152 log n(NH3) + (n - I)log55.5 (1)

The factor of 1.152 takes into account the inductive effects of the ethylene bridges of the chelate ring, while the (n - I)log55.5 term takes into account the asymmetry of the standard reference state. For chelating ligands containing the pyridyl group, the formation constants are anomalously high (R.D. Hancock and G.J. McDougall, J.C.S.(Dalton), in press) in terms of an equation such as (1), but relating, for example, bipyridyl formation constants to those of the anlogous pyridina complexes. The reasons for this are related to the steric requirements of the coordinated pyridine molecule. However, empirical modelling of these constants is still possible if ari~effective stability is assumed for the pyridyl group in chelating ligands (logK.. (pyridyl)), such that

logKj(pyridyl) = k logKj(bipyridyl) + - lOg55.5 (2)

is a constant equal to 0.5 for all nitrogen-donor chelates with five- membered rings, and is thought to have the significnace of steric strain. loglL (pyridyl) can be estimated as -0.1 for La(III) from logK. 3.6 for La(III) With picolinic acid using the appropriate equations. From (2) this suggests that logK-(bipyridyl) for La(III) should be 0.9. Glass electrodes were used to measure this constant in 0.5M NaNO, at 25 C, where logK. 1.06, +_ 0.03 was found. The equations analogous to (1) for aminocarboxylate ligands (e.g. EDTA) are used to estimate the affinity of La(III) and the other lanthanides for nitrogeiftfotior ligands, particularly ammonia, and are also used to examine trends in coordination number among the lanthanides. Thus, logK.(NH,) 0.7 for La(III) is estimated, and complexes of La(III) appear to be consistent with a coordination number of eight. lation of the Mossbauer parameters suggest that the ff_back-bonding is changing along the series of complexes.

M.A.De Paoli thanks the Humboldt Foundation for a research fellowship.

246 V.8 ULTRASONIC ABSORPTION MEASUREMENTS AS A PROBE OF LANTHANIDE SOLVATION IN MIXED SOLVENTS H. B. Silber —-—-~^ mi Division of Earth and Physical Sciences, The University of Texas at San Antonio, CYCLC San Antonio, Texas, USA. G.A. Schoc A question of continuing interest in the solution chemistry of the lanthanide series is whether a solvation number change occurs near the middle of the series. Assuming Ujjai the existence of this solvation number change, there are two different viewpoints concerning its appearance. The first explanation is that there is a different All c solvation number for the solvated cations within the series, with a region in the denta middle where two forms of sclvated cations are in equilibrium with each other, differing in the number of bound 'solvent molecules. The second states that the The s solvation number of each lanthanide cation is the same in solution, but that when a lanthanide complex forms, more solvent molecules are released for the heavier deter lanthanides than for the light ones. C10^ Our investigations using the ultrasonic absorption technique in mixed solvents has techn provided some insight into the different mechanisms. The excess sound absorption is (ioni proportional to the concentrations of reacting species times the square of the reaction volume change. By measuring the absorption in solutions of constant salt stabi composition as a function of solvent composition, any solvation number change is Scatc detected as an abnormally large excess absorption. In aqueous methanol using erbium(III) as the cationic probe, no change in solvation was found when chloride is stati the ligand whereas this change occurs for the nitrate (J. Reidler and H. B. Silber, of 1: J.C.S., Chem. Comm., 354 (1973)). A similar solvation number change exists for perchlorate ion (H. B. Silber, J. Phys. Chem., 78_, 1940 (1974))and for iodide ion. The e Our initial results using bromide ion are not yet conclusive. These data are interpreted in terms of a change in lanthanide solvation number occurring during the corre complexation process and this change appears to be caused by steric crowding within analy the inner solvation shell. kinet The extension of these measurements to other lanthanides within the series indicates order that with some cations a solvation number change can occur when chloride is the ligand. Similar results have been obtained for other lanthanide nitrates and perchlorates. entro For all three ligands, there were significant differences observed between the light (J. 2 and the heavy lanthanide ions. This may indicate the existence of a difference in the solvated cation superimposed upon the solvation number change occurring during The I complexation. in th The rate constants for lanthanide complexation reactions have been obtained with chargi several ligands. The mechanism of complexation in the mixed solvents appears to be similar to that observed in water and the complexation rate constant is within as O.i experimental error of the water values. These studies are being extended to similar systems in aqueous DMSO, but only preliminary results have been obtained. C A 0

V.9 247

A PHYSICO-CHEMICAL STUDY OF YTTR1UMC£MP1EX WITH ALL-cis-1,2,3,^- CYCLOPENTANETBTRACAR1SOXYLIC AC 1IT G.A. Rama Rao and K. Srlnivasulu School of Studies in Chemistry, Vikram University, Ujjain, M.P. India. ^56010

All cis-i^jSj^-cyclopentanetetracarboxylic acid (CPTA) as a quadri- dentate ligand has been of great interest in coordination chemistry. The stability constants of the complex of CPTA with yttrium are determined at different ionic strengths potentiometrically at 25°C in CIO^ background in a pH range of 3.5-^.2 employing Irving and Rossotti technique. The mean distance of approach of ligand to metal ion (ionic interaction parameter) is evaluated as 3,if A0 with the data of stability constants in the range O.O5-O.23M C10^ ionic strength using Scatchard modification of Bronsted-Christiansen equation and by statistical treatment of the data. This value confirms the formation of 1:1 metal to ligand stoichiometry as obtained by other methods. The elemental analysis of the solid complex, isolated at ^.5 pH, corresponds to a probable formula ML.7H20. The theraogravimetrie analysis indicated that the complex is stable up to 25O°C. The kinetic parameters like apparent activation energy (=30 K Cal/mole), order of decomposition (=1), frequency factor (=13.7) and activation entropy {=-1.77) are calculated using modified Doyle's method (J. Zsako, J. Phys. Chem., 7J2, 2*fO6 (1968) from the thennogram. The I.B. spectrum of the solid complex suggests that the bonding in the complex is partially ionic type. The effective nuclear charge and percentage J^onic_character in the complex are calculated as 0.6 and 56.5 respectively by X-ray edge absorption studies. 1if 248 V.10 / COMPLEXATION OF LAN THAN I£ES--BY AMINOCARBOXYLATE LIGANDS. y C00RDI1TJ / II. THERMODYNAMIC PARAMETERS / CARBOXTl G. R. Choppin, M. P. Goedken and T. F. Gritmon IT.A. Kos Department of Chemistry Florida State University Institui Tallahassee, Florida 32306 U.S.A. The values of the free energy, enthalpy and entropy of complexation Lan1 in difft are reported for a series of aminocarboxylate ligands. For all th« of the c systems, a region of "compensation" between AH^ and ASj exists with the between Nd(III) and Ho(III) which is related to dehydration effects. 7/e 1 of lantt The entropies are a function of the number of ligand carboxylate octadeni: groups coordinated. Correction of the enthalpy for the coordination and prot of the carboxylate groups gives a residual enthalpy which is a The 1. ] linear function of the basicity of the nitrogen groups. In the tion nun HEDTA complexes, the data are consistent with outer sphere coordination number of the alcohol group in the light lanthanides and with inner sphere Two com for the coordination in the heavy members. coordin coincid metal i 2. trident all Ian complex are app 3. as in t (for al the out UPPA; t lanthan* producing tion,pH<*i. two steps of phenols

F7 J?p V.R.2 249 PHAK // COORDINATION MJMBEKS OF LANTHANUMS IN COMPLEXES V.'ITH POLYAMINOPOLY- (IDE (1 / CARBOXYIIC ACIDS r~- "~~" I SUV N.A. Kostromina, N.n. Tananayeva and T.V. Ternovaya Institu Institute of General and Inorganic Chemistry, Kiev, USSR

Lanthanide ions are known to exhibit different coordination numbers in different compounds. There is also information about the variation Ad of the coordination numbers in the lanthanide series for complexes formula with the same ligands. were pr V/e have carried out a study to determine the coordination numbers visible of lanthanides in complexes with hsxadentate (iilffA, CDPA, KJ3HTA) and X-ray p octadentate (UTPA) polyaminopolycarboxylic acids by spectrographic Ac and proton resonance methods. carbony The results obtained may be oumciarized as ''ollovvs: triposi 1. In equimolar complexes with hexsdencate ligands, the coordina- Th tion numbe' decreases in the lanthanide series due to decrease in tne a behav number of water molecules contained in. the complex (from 3 to 0). in acet Two complex forms of different hydrate composition have been detected of ions for the middle member of the series. In the complex with ECPA, the X- coordination number is eight for the whole lanthanide series and coincides with the number of ligand donor groups coordinated to the corresp metal ion. Ln(PF6) 2. In complexes that include two hexadentate ligands or hexa- and >' tridentate ligands, the coordination number eight remains constant for all lanthanides; water is not contained in the inner sphere of the complex, The distances to the donor atoms for yttrium group lanthanides: / are approximately as long as in the cerium group. ; 3. In Mnuclear complexes with Di'PA» "uhe inner sphere is the same i as in the original LnDTFA complex with the coordination number eight * Supp< (for all ianthanides); the second lanthanide ion is coordinated in the outer sphere via the terminal carboxyl groups of the complexed Iff PA; the coordination number of the second ion decreases in the lanthanide series. producing hydroxy] radicals, hydrogen peroxide and Mn{I Il)SB,when exposed to acid solu-

tion>pH<4.5. The dimers act as one electron oxidizing agents, in one step for type I and two steps for type II dimers and are homogeneous catalysts in the oxidative coupling of phenols.

250 V.R.3

HANIDE HEXAFLUOROPHOSPHATE ADDUCTS OF N,N,N'/N'-TETRAMETHYLADIPA- cTADDUCTS IDE (TMAA) * ^/PHOSPHIl R. Isuyama, W.de Ollveira and G.Vicentini Instituto de Quimica, Universidade de Sao Paulo Institu- Sao Pau! Adducts of lanthanide hexafluorophosphates and TMAA, with general Ii formulas Ln(PFg)3.4TMAA (Ln» La-Nd) and Ln(PFg)3.3TMAA (Ln= Sm-Lu,Y) were prepared and characterized by elemental analysis, infrared and perties visible spectra, molar conductance measurements in acetonitrile and neral fc X-ray powder patterns. Dy-Lu, : TI According to infrared spectra the TMAA is bonded throught the high hyc carbonyl oxygen and the PF~ ions are not coordinated to the the P-0 tripositive lanthanides. P-N str« The conductance data in acetonitrile and nitromethane indicate ligand, a behaviour of 1:3 electrolytes. Equivalent conductance measurements lanthani in acetonitrile, at various concentrations, suggest the existence and two of ions pairs in concentrated solutions. one or -t X-ray powder patterns show two series of isomorphous compounds, symmetry corresponding to the adducts of formula Ln(PF,),.4TMAA and are coor to lutet Ln(PFg)3.3TMAA respectively. and one Td symme ).• Th accordan Th compound

Ln(C104) * Supported by FAPEEP

* Suppo: V.ll 251 V. 'DUCTS OF LANTHANIDE PERCHLORArES AND TRIS (1-(2-flETHYL)-AZIRIDINYL .y7PH0SPHINE OXIDE (TMAPO) G.Vicentini, J.C.Prado, R.Najiar and A.B.Nascimento Instituto de Quïmica, Universidade de Sâo Paulo, Caixa Postal 20.780, Sao Paulo, Brasil.

In this comunication we wish to report the preparation and pro- perties of the adducts of .I.anthanide perchlorates and TMAPO, with ge-

neral formulas Ln(ClO4)3.4TMAPO (Ln= La-Tb) and Ln(ClO4)3.6TMAPO (Ln = Dy-Lu, Y). The infrared spectra presented very weak water bands, due to the high hygroscopic character of the substances. A considerably shift of the P-0 stretching mode to lower frequencies and a small shift of the P-N stretching mode to higher frequencies, in relation to the free ligand, indicate coordination through the oxygen. The compounds from lanthanum to presented two bands in the region of -1100 cm" and two bands in the region of ~620 cm ; the one at -620 cm contain one or two shoulders, this fact is indicative of a lowering of the Td symmetry of the perchlorate ions, showing that at least in part, they are coordinated to the lanthanides. For the compounds from to lutetium and yttrium only one band (v.) is observed at -1040 cm -1 and one band (v4) with a shoulder at -620 cm / indicating that the Td symmetry was maintained. The conductance data in nitromethane and acetonitrile are in accordance with a behaviour of 1:3 electrolytes. The X-ray powder patterns showed two series of isomorphous compounds: the first series corresponds to the compounds of formula

Ln(C104)3.4TMAP0 and the second to that of formula Ln(C104)3.6TMAPO.

* Supported by FAPESP 252 V.12 I ABSORPTIC INFLUENCE OF BRANCHING IN THE C H CHAIN ON THE STOICHIOMETRY AND STRUC- COMPOUNDS TURE OF COMPLEXES OF DIBUTYL SULFDXIBES WITH L^NTJjANIDE__E6RCHL0RATES L.S. Teixeira*, V.K. Lakatos Osorio and E. Giesbrecht N.K. Davidi Instituto de Qufmica, Universidade de Sao Paulo The Pisarz Caixa Postal 20780 - Sao Paulo, Brasil of the Ukr The absorpl Recently, we described the synthesis and some properties of the the EuClII' studied. T complexes Ln(C10 ) ,6(n-Bu) SO, where Ln * La - Nd, Sm - Lu, and Y, and tes in aoli (n-Bu) SO * di-n-butyl sulfoxide (V. K. Lakatos Osorio and A. M. Passos -absorptioi ratio metj Felicissimo, Inorg. Chim. Acta 19, 245 (1976)). We are now extending the shows the < of the ban< study to the corresponding complexes with di-tert-butyl and di-iso-butyl individual sulfoxides. Diketone With (t-Bu) SO, the bulkiest of the three sulfoxides under study, designatioi only 4 molecules can be accommodated around the lanthanide ion, leading RjCOCH^OR. to the complexes Ln(C10) .4(t-Bu) SO, where Ln - La - Nd, Sm, Eu, Tb and Dy. In all of them, evidence for the occurrence of both coordinated H(aca) and ionic perchlorate groups was obtained. Infrared spectroscopy indi- H(bac) cated that as the ionic radius of the lanthanide ion is shrunken within the series, bidentatB perchlorate coordination (c symmetry) is pro- H(dbm) Zv H(tta) gressively replaced by monodentate perchlorate coordination (C symme- 3v H(hfa) try). These results contrast with those observed for the (n-Bu) SO com- H(tdm) plexes, in which cases, the perchlorate groups are essentially ionic (T symmetry) for the heavier lanthanides (Tb - Lu and Y), but partial- *) small ly coordinated (with probably C symmetry), for the lighter metals. In accordan 3v nates the c nes^as H(ac 7 With (isp-BU.) SO, two series of compounds can be obtained, accord- the FQ— 5 •ean values ing to experimental conditions. The compounds, prepared under anhydrous conditions, show a metal to sulfoxide ratio of 1:5. If dehydrating a- the new flo The Eu(III) gents are not added during the synthesis, compounds with 1:6 metal to •olutions a; sulfoxide ratio are obtained.

*Instituto de Quimica, Universidade Federal da Bahia Salvador, Bahia, Brasil X 1 V.13 253 ABSORPTION SPECTRA AND STRUCTURE OF COORDINATION COMPOUNDS WITH g-DlKETONES IN SOLUTIONS N.K. Davidenko, K.B. Yatsimirskii, A.G» Goryushko ...'„.•••••'• The Pisarzhevskii Institute of Physical Chemistry of the Academy, of Sciences, Departam of the Ukr.SSR, Kiev, USSR Recife, The absorption spectra of the aqua-methanol (90 vol.pet Ch,OH) solutions containing The comp the Eu(III) coordination compounds with 3-diketones of different structure have been studied. The individual ab^rption spectra of, the Eu(III)mono-,bii- and tris-6-diketona- ions and tes in solutions have been calculated according to the evidence concerning ligh -phenant -absorption of solutions containing mixtures of coordination compounds of different ratio metal :ligand and stability constants of these compounds. The table below [Ln (LH) shows the composition of the @-diketones_studied as well as positions of the maxima of the bands Ctfnax) found in the region F - D of Eu(III) transition in the N-oxide individual absorption spectra. ° ° The new i vibratioi Diketone F _ T) Eu(III)transition, cm V max o - The osci: designation ~ 0 R 2 R z 1 G7/2, o: RlC0CH2C0R2 l 2 Eu(6-diket) " " Eu(B-diket)3• were foui 17303 Chem. So< H(aca) CH3 CH3 17280 s.s *) 17261 solution the mechj H(bac) CH3 C6H5 17279 17306 17257 17268,17256 inforraat: H(dbm) 17277 17312,17256 s.s. C6H5 C6H5 spectra i also inv« H(tta) W CF3 17271 17278,17256 s.s. that is i H(hfa) CF CT 17267 17257 s.s. 3 3 experimer

U(tdm) C4H3S CF2OCF3 17268 17269,17253 17269,17253 mechanisn discussec *) small soluble In accordance with nephelauxetic band shifts in the absorption spectra of mono-3-diketo- nates the covalence of the -ligand bond is increased in the series of f3-diketo- nes,as H(aca)-sH(bac>cH(dbin)

SYNTHESIS AND SPECTROSCOPIC STUDIES OF LANTHANIDE CHELATE COMPLEXES. G.F. de Sa, A.A. da Gama, M.A. de F. Gomes and R. Ferreira Departamento de FTsica - Universidade Federal de Pernambuco-50.000 Recife, PE-Brasil. The compounds formed in the reaction between a mixture of lanthanide ions and 2-Pyridylcarbinol N-oxide with 2,2-dipyridyl and with 1,10- -phenantroline were isolated and studied. The compounds of formula Ln= [Ln (LH)3 dipy] and [Ln (LH)3 phen], where LH = 2-pyridylcarbinol N-oxide and Ln = Pr, Eu and Nd,are solid crystaline substances. The new chelates were characterized by means of chemical analysis, vibrational spectrum, and electronic absorption and emission spectra. The oscillator strengths of the hypersensitive transition Iq/?"*" Gc/o» 7/2' °^ t'ie Nd(III) complexes have been studied. These compounds were found to be "shift reagents" for NMR spectra (C.C. Hinckley, J. Chem. Soc, £1, 5160 (I960)). The structures of these adducts in solution are unknown and this prevents a complete understanding of the mechanism by which the "shift reagents" work. Additional information about these adducts was obtained through their emission spectra in the solid state, at room temperature and at 77°K. We have also investigated the emission spectra of the adducts in solution, that is under conditions that approximate closely those of the NMR experiments. Both the contact and the dipolar effects interaction mechanism between the lanthanide ion and the ligand protons will be discussed. V.15 255 i

COMPLEXES OF LAHTHANIDJL-NITRATEP AND ISONICOTINIC ACID HYDRAZIDE (INH) L.B.Zinner*, D.E. Crotty, T.J.Anderson, M.D.Glick

Wayne State University, Department of Chemistry, Detroit, Michigan, 48202, U.S.A.

Complexes of formula Ln(NO3),.3INH.3H-O, were prepared for Ln= La, Nd, Sm, Gd, Ho, Yb. According to conductance data in nethanol the compounds present a behaviour of 1:1 electrolytes. Shifts of v and v to lower frequencies in relation to the free ligand, and six bands attributed to the nitrate group were observed in the infrared spectra. A single-crystal structure determination for the Sm derivative

(P21/n, a= 11.805 (2); b= 16.050 (4); c= 16.058 (3) and 5= 100.47(1)) shows the complex to be discrete nonacoordinate cations with three bidentate INH groups and three water molecules coordinated. The nitrate ions are hydrogen-bonded to the water molecules. The coord:L nation polyhedron is a tricapped trigonal prism. It is noteworthy that the nitrate ions were displaced from the coordination sphere by the competing ligands.

* Universidade de Sao Paulo, Instituto de Qulnica, Caixa Postal 20.780, Sao Paulo, Brasil. Visiting scientist at Wayne State University, sponsorship of Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP). although nearly all imidazole ligands of the resin can be used *o coor

metal ion. 3. Resins of this type can be used to remove traces of metal salts from organic

solutions.

ii —1

256 V.R.4

PMtt STUDY OF INTSixACTIOiTb ifci'ViHEN 07 COMPLEXES OF SILVER (l) J.A.P.Hoi AHL SOME ALKBKfiS OR AKOMAfDICS .»lTn LAaTKAHIDl. SHIFT EEAaLNTS Instituto JAITOWSKE Andraej, BA>IBdKA Anna The Institute of Fundamental Chemical .ProDlems, University of Warsaw, Warsaw, Poland RS(C)CH2C Since the Evans, Tucker and cie villardi L/ described application or Ian* they can thanide shift reagents to alkenes.based on coordination of lantha= aides (Ln) to ST complexes formed oy alicenea and silver salts of (J.Cherc.S pwfluorinated carboxylic acids; the Ln ion is bound trough the melting f oxygen of carbony1 group* isomer. obtained The induced shifts are partly paramagnetic in origin. However, it has no a considerable part of these shirts is diamagnetic due to the for= mation of mulricomplexeo alkene - Ag+ salt - shift reagent. The In order to measure the diamagnetic shifts we investigated where Ln 1 Infrared the system Ln(fodU - styrene - AgOOCCS ^ /where Ln * Laf isuj fod = C-F, ,COCIICOC (.CH-.),-/. The total induced shift /observed for the donor Eu(fodV at molar ratio of styrene : Ag+ : JSu(foaU = 2:1:1/' that the varied from 0,30 ppm for meta and para aromatic protons to 1,1> spectrum ppm for methiue proton or the vinyl group, wnereas the values of indicates diamagiuttic shifts /observed for LaljrodW were in the range of all of wh 0,24 ppm /for methine proton of vinyl group/. Thus, the diamag= that the netic shift cannot be ignored. It is not clear as yet whether more inte the observed paramagnetic shifts are purely dipolar in origin. indicates It is widely known that Ag+ form

V.R.5 257

COORDINATION COMPOUNDS PF LAHTHANIDE PERCHLORATES WITH DISULFOXIDES /CRYSTAL FIEL' * P. Porcher, ( J.A.P.Holanda , E.Giesbrecht, V.K.Lahatos Osorio and O.A.Serra Laboratoire > Instituto de QuTmica, Universidade de Sao Paulo, Sao Paulo, SP Rare earth Dl tical absorp The coordination of lanthanide(III) ions by disulfoxides, FOD chelates RS(C)CH2CH2S(O)R (where r - CHg and C^^) are being investigated. pium compoum Since these sulfoxides have two equivalent asymmetric sulfur atoms, they can exist as ^1_ ancl west) modifications. Nieuwenhuyse and Louw and eveti amoi (J.Chetr.Soc, Perkin Trans. I, 839 (1973)) have shown that the higher A complete ai melting form of bmse (1,2-bis(methylsu1finyl)ethane) is the meso that the cry: isomer. Only one form of 1,2-bis(ethylsulfinyl)ethane (bese) has been ones obtaine( obtained (G.M.Bennett and F.S.Statriarc, J.Chem.Soc, 1684 (1931)) and tes of the d: it has not been assigned to any diastereoisomeric form. but can be a The following compounds have been prepared: [Ln (mej5£-bmse) ] (ClO^) , 4 3 found to be: where Ln * La,Pr,Nd,Sm,Eu,Tb,Ho,Er,Yb and Lu, and [Nd(bese)4] (C1O4)3. ' Infrared spectral data provide evidence for the sulfoxide oxygens as the donor atoms in the coordination of the lanthanides. They also show that the T . symmetry of the ClO^ groups is retained. The fluorescence spectrum of the compound |Eu(meso-bmse)/|] (C10.)3, obtained at 77 K, The 63 exper indicates the possible occurrence of several symmetrical environments, viation of 2 all of which probably belong to the same point group; it also shows as free-atom! that the magnetic dipole transitions (|AJ|* 0,1, except for 0«-K>) are The very larj more intense than the electric dipole ones (|AJ|= 2,4,6). This fact be applied tc indicates the presence of a point group with a center of inversion, 120 I SLJM> perhaps slightly distorted. the 5D ^r Attempts to prepare the correspondinp complexes with _ra_c-bmse Q were unsuccessful. ground FQ e«h 9'// The high vali coordination ces to the li teraction whi depends direc Permanent address: exist for k Centro de CiSncias, Universidade ~°deral do Ceara, Ceara, Brasil. mij.ar sysxems. for nit- trends for LaC a coord:

258 V.16

/CRYSTAL FIELD PARAMETERS FOR RARE EAR! SHIFT-REAGENTS CHELATES. OSCILLAT P. Porcher, 0. Beaury and P. Caro. G.F. de Laboratoire de Bellevue du C.N.R.S. 1, Place A. Briand. 92190 MEUDON FRANCE. Silva Rare earth DPM chelates are well known as shift reagents for NMR applications. The op- Departam tical absorption spectra and fluorescence spectra were recorded for Europium DPM and fe, Pern FOD chelates, and for the Neodymium DPM chelate at temperatures down to 4K. The euro- The f-f pium compounds are characterized by the very large intensity of the usually forbidden crystal a fact DO5? F- transition, close to 5800A, which is unique among europium chelates odd elec and eveii among europium compounds. field. I A complete analysis of the 4K absorption spectrum of the neodymium DPM chelate showed of the c that the crystal field parameters in these substances are very large, comparable to the Certain ones obtained for rare earth oxides. The coordina£ioji~fl.f the rare earth in the two si- Molec. P tes of the dimeric DPM molecules in the solid state is_seveju The symmetry is very low report h' but can be approximated as C, The parameters for a C, crystal field hamiltonian were Nd(III)- found to be: Peacock 1 -1 - - 971 * 40 cm" , B 439 * 86 cm variatio - -1521 - 45 cm"1 , B 1042 - 88 cm-1 glasses consider - - 300 - 60 cm"1 , B 338 - 117 cm"1 B. de B. The 63 experimental Starklevels were fitted whit these parameters to a mean square de- have stu viation of 21 cm . Racah's Tree's and Judd's parameters were used in the adjustement the Nd_(J as free-atoms parameters. have obs The very large values found for the crystal field parameters in the neodymium case can P.R.Fiel be applied to the europium one; and then a complete crystal field calculation involving the expe 120 I SLJM> kets from the F and D levels shows that the very large intensity of expressi the D. ^ F« transition is due to the unusual amount of J-mixing supported by the rfhere P ground FQ state. dipole t: and U< The high values of the crystal field parameters of order k » 2 and 4 are due to the low obtained coordination which is seven instead of eight for numerous chelates and to short distan matrix e ces to the ligands. A consequence may be to enhance contact shift effects through . in- temperate teraction which p electrons because matrix elements such as <*4f I B I | n p) , will consider* depends directly on the values taken by B parameters of order 2 and 4, but do not 323' 29) exist for k it \ 0c\. sic uocu cauxuiaue nits aj.iinj.Ly 01 for nitrogen-donor ligands, particularly ammonia, and are also used to examine trends in coordination number among the lanthanides. Thus, logK.(NH») 0.7 for La(III) is estimated, and complexes of La(III) appear to be consistent with a coordination number of eight.

V.17 259

OSCILLATOR STRENGTHS OF NEODYMHJMXI11 )-DOPED CaF2 AND SrF2 SINGLE CRYSTALS G.F. de S'a, H. Vargas, I.de M. Xavier Jr,W.M. de Azevedo and C.A. Onofre e Silva Departainent of Physics, Universidade Federal de Pernambuco - 50.000 Recj[ fe, Pernambuco-Brasil. The f-f transitions of the lanthanides are "parity forbidden". In a crystal they become allowed by vibronic interaction or by admixture of odd electronic wavefunctions due to the odd parity terms in the crystal field. In the Judd-Ofelt theory the contribution of the odd parity part of the crystal field was considered in mixing states of different parity. Certain transitions termed "Hypersensitive" (B.R.Judd and C.K.J<£rgengen, Molec. Phys. _8, 281(1964), are markdely affected by the environment. We e report here the oscillator strengths (PgXp^ °f ^ ^"^ transitions of Nd(111)-doped CaF2 and SrFg crystals, and briefly discuss the results. Peacock (R.D. Peacock, J.C.S. Faraday II, 6_8, 169(1972)) has studied the variation of f-f hypersensitive transitions in Eu(1111 and Ho(III) solid glasses with respect to the temperature. A positive (—\m P) is considered an evidence for a vibronic mechanism. Sa et al (G.F. de Sa, B. de B. Neto and R. Ferreira, Inon. Chim. Acta, _20_ (1977) in press) have studied the temperature dependence of the oscillator strengths of the NdjJS) complexes__in aqueous solution in the range 25° to 90°C and have observed a slight decrease in Pexp with T.Carnal et a^L (W.T, Carnal!, P.R.Fields and K. Rajnak, J. Chem. Phys. 4_9_, 4412(1958)) have correlated the experimentally determined band intensities with a theoretical N N 2 expression derived by- Judd: P = E Tx( f ^j||U^'|| fif)'J ' ) , X = 2,4,6 rfhere P is the oscillator strength corresponding to the induced electric dipole transition, between the levels #J •+ iiVJ1 at energy a (cm ) and U^ ', is a tensor operator of rank X. From our experimentally obtained oscillator strengths and theoretically calculated reduced matrix elements of Carnall, we have obtained the T. coefficients. The temperature dependence of the intensities of the f-f spectra is considered. The spectra of crystals have been obtained at 37 3°, 348°,

323C 298°, 273° and 77°K. / 260 V.18

EMISSION SPECTRUM OF Cs2NaEu(N02)& /DERIVA S. C. Kuo and L. C. Thompson / Andrze Department of Chemistry University of Minnesota, Duluth Instit Duluth, Minnesota USA Warsaw There are very few complexes of the lanthanide elements that are known to have octahedral, six-coordination. Recently, however, the elpasolite compounds Cs2NaLnClg, in which the lanthanide has this coordination, have been studied The fl quite extensively by various spectroscopic and magnetic methods and our knowl- edge of the behaviour of the lanthanides in octahedral coordination has been /in et: substantially increased. As an extension of our previous work with Cs2NaEuClg (0. A. Serra and L. C. Thompson, Inorg. Chem., 15_, 504 (1976) and 0. A. Serra, ligand L. C. Thompson, and J. A. Koningstein, Chem. Phys. Lett., in press) we have now measured the emission spectrum of CsJNaEu(NOp),. In this compound the europium(III) vided : is coordinated octahedrally by the nitrogen atoms although the symmetry is T^ if the oxygen atoms are included. The emission from the compound is extraor- minesci dinarily intense and is brilliant orange in color. The intensity is substantially greater than that observed from Cs-NaEuCl, which is probably due to the more /which efficient energy transfer paths provided By the nitrite ions. The triplet tran- sition in Ln(N02),_~ at 23>500 em" has a relatively large molar absorptivity excite (J. C. Barnes andTl. D. Peacock, J. Chem. Soc. (A), 558 (1971)) and is most likely responsible for the energy transfer. The emission has been excited by using the ligand 2537, 3130, 3650, 4047, and 4358A lines of a mercury lamp. state. Since the Eu(N0_), moiety has a center of" symmetry, the electronic spec- trum is, as expected, Sominated by transitions which obey magnetic dipole selec- Eu(lII 1 tion rules and have AJ=±1. These are the D--* F.. transition at 5927A which is spectr very sharp and approximately ten times more intense than any other transition 5 7 state and the very much weaker emissions from the second excited state !>.-*• Fn and 5 7 • - v and fr D..-*- F_, the latter consisting of the expected two sharp components. A series of 5 7 vibrational transitions is found when the D + F. electronic transition is exam- Ligand 5 7n ined under increased sensitivity. The DQ->- F« electric dipole transition occurs only as a relatively weak vibronic transition. Additional weak vibronic transi- transi 5 7 5 7 tions are observed for DQ->- F, , and D.,-* F.. , , g. comple Although the main features of the spectrum are accounted for nicely in terms 5 7 of a geometry having inversion symmetry, the existence of a weak, sharp DQ-* FQ transition implies that there is a slight distortion in the coordination geometry. In addition there is also a series of vibrational lines that appear on both sides of this transition and can be clearly identified. Preliminary measurements of the emission spectrum of the analogous compound, tb2NaEu(N02)^ give results that are essentially identical to those of CsJteE^ fith the exception of a shift of the magnetic dipole allowed transitions Dy 2 to 3 Angstroms tosard longer wavelengths. V.19 261

V • EMISSIOE N SPECTRA OP LANTHANIDE COMPLEXES WITH ORGANIC LIGANDS, /DERIVATIVES OP TRIPH^NYLMETHANE DKES AndrseJ JANOWSKI and Jadwiga RZESZOTAflSKi' Institute of Fundamental Problems in Chemistry, University of Warsaw, Warsaw, Poland

The fluorescence and phosphorescence spectra of the complexes /in ethanol solution/ as well as the energy transfer from the ligand to the central ion were studied. The Uganda can be de- vide d into two groups: symmetrical /which showed molecular lu- minescence from the second excited state/ and antisymmetrical /which showed molecular luminescence from the first and second excited states/. The complex-formation with antisymmetrical ligands quenched molecular luminescence from the first excited state* The energy transfer was observed for the Tb(lll) and Eu(lll) complexes with symmetrical ligands only. Thus, the spectra showed atomic emission due to transitions from the *D* 7 7 7 7 7 state of Tb(lll) to Pg, Pg, P4, F3 and P2 states and from the ^DQ state of Eu(lll) to 7?2 and 7P^j states, 7 7 Ligand-field splitting of the ^Do •—&• P2 and ^DQ —•*>» P-j transitions of Eu(lllj indicated hexagonal D^ symmetry of the complexes with symmetrical ligands.

^\ m II 262 V.R.6 COORDINATION OF THE LANTHANIDE IONS WITH PYRAZINEAMIDE.

M.A.V. de Almeida, G.F. de Si and O.A. Serra Author Abbasi, S Departamento de FTsica - Universidade Federal de Pernambuco - 50.000 Abu-Dari, Aikawa, N Recife, PE, Brasil. Airoldi, < A new series of coordination compounds be 1ween the lanthanide ions and Alexanyan Allison, v pyrazinamide (PyNHg), has been prepared. The composition of the Allmann, 1 complexes was established by analysis of the lanthanide con "tent, mi- Almeida, 1 Al-Niaimi cro analysis, conductivity, Raman and IR spectra, and absorption and Altmeppen, emission electronic spectra. The assigned vibration frequency of the Alves, 0.] Amaral, L C=0 bond indicates that the carbonyl group is coordinated to the metal Amorin, A, ion. In "the case of 1he neodymium complex there is a strong hypersen- Anacona, i Anderegg, sitive effect on the l9/2 ' 4G5/2 '7/2 transition. We have studied Anderson, the temperature dependence of the oscillator strengths (Pexp) °f Andrade, I Angelos, £ Nd( HI)complexes in aqueous solution in the range 25° to 90°C. We have Anichini, observed a slight decrease in Pexp with T. The europium and terbium Aoyama, Y Araujo, N complexes luminesce very strongly both at room temperature, when Araujo F9 excited with near ultraviolet radiation (G.A.Crosby, R.E. Whan and R. Ashworth, Asperger, M. Alire, J. Chem. Phys. _34, 743(1961)). In the europium complex the Attanasio most intense transition is ^Do + 'F2 followed by ^Do .».7 F]. The Avanzino, Aymonino, former transition is split in two components and the latter in three Azevedo, components. B&chmann, Baggio-Sa: Ballivet, Banerjea, Baraga, M Baranovsk: Barbucci, -.11 Barros, H. Basak, A.I Battiston; Bauf R. Baztan, J. Beaury, O. Behrens, I Bellitto, Bencini, A Benedetti, Berezin, J ,•

263

AUTHOR INDEX Author Author Page- Author Page Ciliberi Clark, ] Abbasi, S.A. " 170 Bersuker, I.B. 124 Clay, R Abu-Dari, K. 152 Bertini, I. 154 Coe, C.( Aikawa, N 212 Berwerth, E.C. 73 Camassel Airoldi, C. 207, 243 Bessier, K.E. 218 Condore! Alexanyan, V.T. 28 Bhatia, J.C. 105 Contant, Allison, J.L. 145 Biddau, M. 123 Copenhai Allmann, R. 211 Billard, C. 24 Costa, l ( Almeida, M.A.V. de 262 Binger, P. 136 Costamac I Al-Niaimi, N.8. 46 Biran, C. 90 Costas, Altmeppen, D. 58 Blesa, M.A. 101 Cracium Alves, O.L. 108 Blum, S.E.C. 60 Cristiai Amaral, L. do 89 Sonnet, J.J. 234 Crotty, Amorin» A.M.M. 179 Boschmann, E. 239 Csontosj Anacona, J.R. 111, 115 Boucher, L.J. 236 Curtius, j I Anderegg, G. 244 Bradley, D.C. 207 Cygon, h 1 Anderson, T.J. 255 Bratushko, Y.I. 41 1 Andrade, H.A.S. 171 Brits, A.G. 92 Angelos, S.G. 40 Bruder, H. 138 Dahl, J. Anicbini, A. 131 Bunel, S. 156, 162 Dambska Aoyama, Y. 36 Bunton, C.A. 156 Darensbc Araujo, N. de 183 Burch, R. 80 Dartigu« Araujo F9, V. 65 Burrows, A.L. 66 Dartigu« Ashworth, T.V. 32 Buslayev, Yu. A. 200 Daviden* Asperger, S. 99 Butsow, J.J. 18 Davydovê Attanasio, D. 49 De Filii Avanzino, S.C. 203 Dehand, Aymonino, P.J. 101 Cabrai, J. de O. 165 Del'Acqi Azevedo, W.M. de 259 Cabrai, M.F. 165 Del Cant Cali, R. 222 Denti, C Cardoso, M.H.M.F. 44 De Paoli Bächmann, K. 173 Cariâti, F. 143 Deplano, Baggio-Saitovich, E. 232 Caro, P. 48, 258 Devillar Ballivet, D. 24 Carroll, J.A. 79 D'Hem, C Banerjea, D. 196 Castro, M.L. de 107, 194 Dias, G. Baraga, M.A. 124 Chacko, J. 186 Diaz, A. Baranovskii, I.B. 167 Chagas, A.P. 243 Diaz, J. Barbucci, R. 223 Chakravarty, B. 106 Di Castr Barros, H. 82 Chapmann, J.E. 104 Dieck, E Basak, A.K. 196 Chasan, D.E. 54 Dikareva Battistoni, C. 102, 192 Chatt, J. 19 Doadrio, Bau, R. 147 Chatterjee, S. 59 Dockal, Baztan, J. 114 Choppin, G.R. 248 Dolcetti Beaury, 0. 258 Christensen, J.J. 43 Dovgei, Behrens, H. 233 Chum, H. L. 70, 71 Dowerah, Bellitto, C. 127 74, 91, 107 Bencini, A. 5i 194, 201 Edwards, Benedetti, A.V. 91 Chudzynska, H. 207 Berezin, I.V. 137 Eichhorn Ciabrini, J.P. 204 Eldik, R Suppoi

264 T

Author " Author Page Author Page Geliert, Ciliberto, E. 202 Elhenawi, M. 116 Ghanekar, Clark, P. 18 El Seoud, O.A. 89 Ghedini, Clay, R.M. 131 El-Shazley, M.F. 85 Ghirvu, C Coe, C.G. 236 Enemark, J.H. 149 Gielen, ^ Camasseto, J.V. 35 Erno, B. 45 Giesbrect Condorelli, G. 202 Espersen, D. 178 Contant, R. 204 Estes, W.E. 52 Copenhafer, W.C. 140 Evers, A. 245 Giovanni* Costa, A.C.S. 179 Glick, M. GZowiak, Costamagna, J. 132 Fabbrizzi, L. 131 Costas, M. 75 Goedken, Fachinetti, G. Goedken, Craciunescu, D. 144, 148, 153 Farrell, N. Cristiani, F. 64 ;: Goel, R.C Faucher, M. 48 Golding, Crotty, D.E. 255 Feliclssimo, A.M.P. Csontos, G. 96 188 Golub, A. Ferreira, A.M. da C. 72, 76 Golubnich Curtius, A.J. 177 Ferreira, R. Cygon, M. 185 254 Gomes, M. Finocchiaro, P. 155 Gonçalves Fiorani, D. 55 Gordon, G Dahl, J.H. 178 Fischer, E.O. 3 Goryushkc Dambska, A. 256 Fischer, D. 216 Gouzerh, Darensbourg, M.Y. 80, 82 Flamini, A. 127 Greis; O, Dartiguenave, M. 121 Floriani, C. 90, 117 Greiser, ' Dartiguenave, Y. 121 Fulck, E. 12 Grevels, ) Davidenko, N.K. 253 Fournier, M. 204 Grevtsew, Davydova, S.L. 20 Fragalä, I. 202 Griffith, De Filippo, D. 78 Franco, D.W. 100 Grim, S.C Dehand, J. 230 Froelich, J. 18 Gritmon, Del'Acgua, A. 180 Fruchart, J.M. 204 Grünter, Del Canto, H. 162 Fruehauf, H.W. 68 Gushikem. Denti, G. 27 Frunze, E.I. 124 1 : De Paoli, M.A. 68, 232 Fujita, M. 157 :• : Deplano, P. 78 Füller, H.J. 151 Ha im, A. ; Devillanova, F.A. 64 Funk, R.L. 31 : Hainberge D'Hem, C. 121 Hall, J.I ! Dias, G.H.M. 65 Gabryszewski, M. 221 Hancock, : Diaz, A. 78 Galf, Yu. L. 119 Hase, Y. Diaz, J.A. 158 Gagné, R.R. 145 :: Hasse, K. 1 Di Castro, V. 102 Galembeck, F. 65 Hatada, h ; Dieck, H. torn 138 Gallais, F.G.. 21 J Hatfield, : Dikareva, L.M. 167 Galy, J. 234 Helene, Doadrio, A. 114, 148, 153 Gama, A.A. da 254 Henke, W. Dockal, E.R. 91 Garbousova, I.A. 28 Hillard I * Dolcetti, G. 27 Gardini, M. 49 Hodgson, : Dovgei, V.V. 47 Garnier, A. 144 Holanda, ; Dowerah, D. 84 Garnier, F. 95 Holanda, - Gasser, 0. 151 Hfljer, G. Edwards, J.O. 37 Gatteschi, D. 51 Horiuchi, Eichhorn, G.L. 18 Ga£o, J. 118 Horta, A. Eldik, R. van 92, 97 * Supported by FAPESP *Instit Saluad

-' ^ÊC ' ,ui•-! : -".

265

Author- Page Author Pag Author 1 Geliert, R.W. 147 House, D.A. 189 Kuya, M. I1 Ghanekar, V.O. 168 Hulsbergen, F.B. 169, 242 Kuznetsc Ghedini, M. 27 1 Ghirvu, C. 114, 153 lamamoto, Y. 129, 176 Gielen, M. 23 Ibarra, C. 156 Labarre, Giesbrecht, E. 7, 103, 187 Inoue, H. 12 La Ginea 210, 212, 215 Ir1er, w. 57 Lamb, J. 252, 257 Irving, H.M.N.H. 6 La Monic Giovannitti, B. 27 Latour, Glick, M.D. ',; 255 Isuyama, R. 250 Izatt, R.M. 43 Lavigne, GZowiak, T.v> 237 Legg, J. Goedken, V.L. 130 Leite, M Goedken, M.P. 248 Jaftowski, A. 256, 261 Leopold, Goei, R.G. 205 Jambor, L.G. 172 Lenarcik Golding, X.R. 28 Jeannin, S. 238 Levey, G Golub, A.M. 228 Jeannin, Y. 62, 238 Librando Golubnichaya, M.A. 16 7 Jensen, A. 178 Lichtig, Gomes, M.A.F. 254 Jezierski, A. 50 Lima, F. Gonçalves, Z.C. 171 Jolly, W.L. 203 Lister, Gordon, G.C. 130 Jordan, R.B. 45 Livingst Goryushko, A.G. 253 Louie, S Gouzerh, P. 62 Loutelli y Greis, 0. 231 Kanellakopulos, B. 57, 77 Louw, W. 1 Greiser, Th. 213 Karayannis, N.M. 54 Luchinat 1 Grevels, F.W. 68 Katz, N.E. 101 Lux, G. Grevtsew,, A.M. 128 Keim, H. 190 Griffith, W.P. 150 Khan, B.T. 25 Grim, S.O. 109 Khann, R.K. 109 Maeda, M Gritmon, T.F. 248 Khar itonova, G.S. 133 Malatest Grünter, K. 96 Khavrjutschenko, V.D. 228 Mammano, Gushikem, Y. 108 Kinzel, A. 138 Manasser Kirschner, S. 5 Mandl, J Klenze, R. 77 Maravign Haim, A. 94 Koglin, E. 231 Marchett Hainberger S.J., L. 183 Kokunov, Yu. V. 200 König, E. 57, 77 Marchon, Hall, J.P. 150 Marcotri Hancock, R.D. 226, 245 Koningstein, J.A. 15 Margalit Hase, Y. 67, 108 Kostromina, N.A. 249 Mares, M Hasse, K.D. 216 Koval, C.K. 145 > J Koz^owski, H. 208 Maroie, 1 Hatada, M.H. 212 Maroso, Hatfield, W.E. 52 Kramerova, S.K. 195 Marsican \ Helene, M.E.M. 201 Krausz, P. 95 1 Krebs, B. 216 Masoud, Henke, W. 211 Massabni 1 Hillard III, R.L. •31 Krishna, V. 217 1 Krüger, C. 68 Massaces Hodgson, D.J. 53 Massart, Holanda, J.A.P. 257 Krumholz, P. 71, 72 Krzysztofik, S. 30 Mastroia 1 Holanda, M.I.D. 71 Matheus, Höjer, G. 75 Kuo, S.C. 260 Mattes, Horiuchi, H. 212 Mattogno Herta. A.M.T.C. 177 Mattos, 1 *Instituto de Qulmica, Universidade Federal da Bahia Salvador, Bahia, Brasil QfrY

1 266

Author Page Author Page Author- Nigam, H. Kuya, M.K. 215 Mauro, A.E. 67 Kuznetsov, N.T. 119 Mazo, G. Ya. 167 Ogurtsov, McDonald, J.W. 149 Ohtaki, î Mehrotra, R.C. 17 Olabe, J. Labarre, J.F. 56 Melios, C.V. 180 Oliveirai La Ginestra, A. 192 Menabue, L. 164 Oliveira, Lamb, J.D. 43 Mendelovici, E. 88 Oliveira, La Monica, G. 120 Mennemann, K. 58, 126 Oliveira, Latour, J.M. 38 Meyer, T.J. 93 Oliveira, Lavigne, G. 238 Migliozzi, E. 192 Oliveira Legg, J.I. 42 Mikhalevich, K.N. 47 Oluka, J. Leite, M.T.P. 165 Miles, S.L. 147 Ortaggi, Leopold, K.R. 94 Miller, J. 83 Osorio, X Lenarcik, B. 221 Mincione, E. 29 Osteryour Levey, G. 37 Mironov, G.S. 195 Owens, C. Librando, V. 155 Mitchell, J.D. 109 Lichtig, J. 182 Mitra, G. 112 Padmanabt Lima, F.W. 174 Miyoshi, K. 160 Palmer, E Lister, M.W. 81 Molina, M. 180 Pandey, V Livingstone, S. E. 61 Moll, M. 233 Paniago, Louie, S. 147 Monaci, A. 166 Pankowskc Loutellier, A. 110 Morazzoni, F. 143 Pankratov Louw, W.J. 104 Morrison, M.M. 39 Paoletti, Luchinat, C. 154 Mornon, J.P. 215 Pasquali, Lux, G. 126 Morsi, S.E. 141 Paul, R.C Moscovici, R. 89 Pavlovic, Moskwitchev, Yu. A. 195 Payne, D. Maeda, M. 214 Moszner, M. 237 Pellacani Malatesta, L. 120 Muir, M.M. 158 Perkins, Mammano, N.J. 85 Müller, G. 126 Perreauli Manassero, M. 120 Müller, R.A. 210 Petragnar Mandl, J.R. 151 Murakami, N.Y. 74 Pfeffer, Maravigna, P. 155 Murakami, Y. 36 Pilon, P. Marchetti, F. 117 Murâti, I. 99 Pinna, R. Marchon, J.C. 38 Mureinik, R.J. 135 Piovesana Marcotrigiano, G. 164 Pitha, J. Margalit, R. 40 Pitombo, Mares, M. 190 Naglef J. 93 Poilblanc Maroie, S. 142 Naiman, A. 31 Pontice13 Maroso, M.L. 83 Nair, C.G.R. 186 Popov, L. Marsicano, F. 226 Najjar, R. 251 Porcher, Masoud, M.S. 116 Nakamura, H. 181 Porta, P. Massabni, A.M.G. 184 Nakajima, M. 38 Poste1, M Massacesi, M. 123 Nakanishi, S. 36 Poyntz, R Massart, R. 204 Nascimento, A.B . 251 Prado, J. Mastroianni, A. 224 Nastasi, M.J.C. 174 Prasad, J Matheus, L.M.M, de 212 Nelson, H.C. 146 Preetz, W Mattes, R. 58, 126 Nettle, Z., A. 209 Preti, C. Mattogno, G. 102, 143, 192 Neves, E.A. 197, 240 Pross, E. Mattos, M.C. 215 Newton, W.E. 149 Nielson, A.J. 150 267

Author Author Page Page Author Nigam, H.L. 217 Pruchnik, F. 30 Put, P.J. v. der 169 Savaria Ogurtsov, I.Y. 124 Pytlewski, L.L. 54 Savy, K Ohtaki, H. 214 Sawyer, Olabe, J.A. 101 Schaffe Rabockai, T. 91 Schenk, Oliveira, A. de 187 191 Oliveira, E. 240, 241 Raman, V.A. Schmid, Oliveira, L.A.A. Ramirez, L.R. 60 Schmidt 103 Rana, V.B. 125 Oliveira, W. de 250 Schnaki Rao, G. 18 Schucha Oliveira, W.A. de 225 Rao, G.A.R. 247 Oliveira Neto, G. de 182 Schulze Rao, K.M.M. 175 Schuman Oluka, J.E. 61 Raymund, K.N. 152 Ortaggi, G. 29 Schwärt Reed, C.A. 235 Schwerd Osorio, V.K.L. 252, 257 242 Osteryoung, R.A. 70 Reedijk, J. 169, Schwoch Recca, A. 155 Scozzaf Owens, C. 54 Reddy, K.V. 25 Seiter, 32 Padmanabhan, M. 122 Reimann, R.H. Sekkina Reinen, D. 211, 219 Sepp, E Palmer, D.A. 190 Reis, J.O.N. 179 Sergeye Pandey, V.N. 87 Rheinberger, V.M. 223 Serra, Paniago, E.B. 44 Rheingold, A.L. 85 Pankowska, H. 48 18 Pankratova, L.N. 133 Rifkind, J.M. Sgamell Rieger, A.L. 37 Sharma, Paoletti, P. 131 140 Pasquali, M. 117 Rieger, P.H. Shin, Y Rieskamp, H. 126 Sievers Paul, R.C. 105 206 Pavlovic, D. 99 Riess, J.G. Sigel, Payne, D.S. 113 Ritter, G. 57 Silber, Pellacani, G.C. 164 Riveros, J.M. 72, 76 Silva, Perkins, P. 31 Rizzarelli, E. 222 Silverm Perreault, R.A. 40 Rocchiccioli-Deltceff, i 62 Singh, Petragnani, N. 35 Rock, M. 74 Singh, Pfeffer, M. 206, 230 Rodrigues, E. 132 Sinha, Pilon, P. 205 Rodrigues, J.F. 65 Singlet Pinna, R. 123 Rodrigues, M. 132 Siracus Piovesana, 0. 127 Rudolph, J. 173 Sirna, Pitha, J. 18 Ryabov, A.D. 139 Sixtus, Pitombo, L.R.M. 129, 176, 241 Rzeszotarska, J. 261 Sladkov Poilblanc, R. 134 Smith, Ponticelli, G. 123 Sä, G.F. de 254, 259, 262 Sone, K Popov, L.V. 128 Sacconi, L. 14 Soria, Porcher, P. 258 Sadikov, G.G. 167 Sosa, B Porta, P. 55 Sähni, S.K. 125 Spitsyn Postel, M. 206 Saiki, M. 174 Spitsyn Poyntz, R.B. 81 Salem, T.M. 116, 193 Sriniva Prado, J.C. 251 Salyn, Ya. V. 167 Srivast. Prasad, J. 217 Sammartano, S. 222 Stcholo Preetz, W. 161 Santos F9, P.F. dos 136 Steffi, Preti, C. 97, 163, 229 Sarry, B. 26 Steffen Pross, E. 135 Sastri, M.N. 191 Steffens Satsny, I.L. 41 Steigen Satyanarayana, K. 175 Stephen! 268 Author Author Page Author Page Savariault, J.M. 56 Strohmeier, W. 96 Vollhar« Savy, M. 48, 142 Sung-Lit, C. 113 Volkov, Sawyer, D.T. 39 Surcouf, E. 215 Volpe, ] Schaffernicht, R. 26 Sustra, A. 99 Schenk/ H.J. 231 Sutton, D. 79 Schmid, G. 86 Svoboda, M. 138 Walker, Schmidbaur, H. 151 Syamal, A. 168 Walton, Schnakig, R. 77 Wandiga Schuchardt, U.F. 136 Warner, Schulze, J. 86 Takagi, M. 181 Warner, Schumann, H. 185 Takeuchi, A. 159 WeigeIt. Schwartz M., M. 209 Tananayeva, N.N. 249 Weiss, ] Schwerdtfeger, H.J. 161 Taqui Khan, M.M. 25 Weiss, 1 Schwochau, K. 231 Tarli, F. 166 Wellemai Scozzafava, A. 154 Taube, H. 4 Wisniewi Seiter, C.H.A. 40 Teixeira, L.S. 252 Wierenge Sekkina, M.M.A. 141, 193, Ternovaya, T.V. 249 Wohlleb« Sepp, E. 233 Thiele, G. 233 Sergeyeva, A.N. 47 Thompson, L.C. 260 Serra, O.A. 73, 129, 176 Tkatchenko, I. 24 Xavier, 184, 257, 262 Tobe, M.L. 16 Tokoro, R. Sgamellotti, A. 143 197 Yakubov Sharma, O.D. 105 Toma, H.E. 103, 198 Yamada, Shin, Y. 18 Tomazic, B. 199 Sievers, R.E. 172 Tondeur, Y. 23 Yamagucl 223 Toralballa, G. 146 . Yamater; Sigel, H. Yamazak: Silber, H.B. 246 Tosi, G. 98, 163, 229 259 Tosi, L. 144 Yared, 1 Silva, C.A.O. e Yatsimi] Silverman, M.A. 37 Trabelsi, M. 110 Trabuco, E. 180 Yatsimii Singh, C.P. 33 Yoneda, Singh, M.M. 84 Tripathi, S.C. 33 Yoshikav Sinha, S.F. 22 Trogu, E.F. 78 Young, Singleton, E. 32 Trzebiatowska, B.J. 13, 50, 208 Siracusa, G. 222 Tsalas, S. 173 Sirna, A. 29 Zakharo^ Sixtus, E. 233 Zanazzi, Sladkov, A.M. 28 Udupa, M.R. 122 Zannini, Smith, T.S. 145 Ueno, K. 181 Zheligo\ Sone, K. 69 Ulbrich, H.H. 210 Zinner, Soria, D. 107 Urdea, M.S. 42 Zinsius, Sosa, B. 148 Ziôtfcows Spitsyn, V.l. 128 Zuber, I Spitsyn, Vict. I. 124 Valentini, F. 62 Srinivasulu, K. 247 Vanin, J.A. 71 Srivastava, S.C. 33 Vargas, H. 259 Stcholokov, R.N. 167 Vaziri, A. 34 Steffè, S. 78 Veiling, P. 26 Steffen, A. 173 Verani, G. 64 Steffens, F. 219 Verbist, J. 142 Steigerwald, H. 96 Vicentini, G. 188, 210, 250, 251 Stephenson, G.R. 66 Vichi, E.J.S. 66, 83 Villa, J.F. 146 Viticoli, S. 55 1/ Evans Coam.

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Author Page Author Page

Vollhardt, K.P.C. 31 Volkov, S.V. 220 Volpe, P.L.O. 243

Walker, N. 80 Walton, E.D. 109 Wandiga, S.O. 63 Warner, B.D. 42 Warner, W.D. 109 Weigelt, L. 96 Weiss, E. 213 Weiss, M.C. 130 Welleman, J.A. 169, 242 Wisniewski, M. 2 20 Wierenga, T.J. 42 Wohlleben, A. 151

Xavier, I. de M. 259

Yakubov, H.M. 227 Yamada, S. 159 Yamaguchi, T. 214 Yamatera, H. 157 Yamazaki, K. 157 Yared, Y.W. 235 • Yatsimirskii, K.B. 41,220, 253 Yatsimirsky, A.K. 137, 139 Yoneda, H. 160 Yoshikawa, Y. 157 Young, R.C. 93

Zakharova, I.A. 119 Zanazzi, P.F. 127 Zannini, P. 16 3, 229 Zheligovskaya, N.N. 128 Zinner, L.B. 188, 255 Zinsius, M. 230 ZiôXkowski, J.J. 237 Zuber, M. 30