Characterization of the Reaction Products of Hydrazine & Phenylhydrazine with Coba1t(II)

Indian Journal of Chemistry Vol. 23A, December 1984, pp. 1044-1045

Characterization of the Reaction following the procedure given by Domnin et al.13 Products of Hydrazine & Phenylhydrazine [m.p.60° (lit. m.p. 59.5-60SC]. Acetylacetonemono- with Coba1t(II), Nickel(II) & Zinc(II) hydrazone schilT base complexes of Co(lI), Ni(II) and Acetylacetonates Zn(II) were prepared as follows: About 0.4 ml of hydrazine hydrate in 10 ml of methanol was added dropwise with constant stirring to a suspension of 1.5 g R C AGGARWAL" & D S SURYA NARAYANA of the hydrated metal(II) acetylacetonate in 30 ml of Department of Chemistry, methanol and heated slowly on a water-bath upto Banaras Hindu University, Yaranasi 221005. 40°C until the suspension was completely dissolved. Received 16 March 1984; revised and accepted 25 June 1984 The complexes, which precipitated on vigorous stirring Complexes of the types M(AcHzh and M(acach(PHzh [M for further 15 min, were suction-filtered, washed with = Co(ll), Ni(ll) or Zn(II); AcHzH = acetylacetone monohydrazone; warm methanol and dried in vacuo. The phei:ylhydra- acacH = acetylacetone and PHz = phenylhydrazine] have been zine complexes were prepared by mixing and stirring prepared by the reactions of hydrazine and phenylhydrazine the methanolic solutions of phenylhydrazine and the respectively with metal(II) acetylacetonates. The complexes have metal(II) acetylacetonate in ~ 2: 1 molar ratio. The been characterised by elemental analyses, molar conductivity, magnetic susceptibility, electronic and IR spectral studies. The complexes, which precipitated almost immediately, magnetic moment and electronic spectral data suggest octahedral were suction-filtered, washed with methanol and dried stereochemistry for Co(II) and Ni(II) complexes. IR spectra indicate in vacuo over cone. H2S04, Prolonged heating or bridging bidentate and monodentate behaviours ofN - N moiety in refluxing of the reaction mixtures containing hydrazine M(AcHzh and M(acach(PHzh type of complexes respectively. or phenylhydrazine resulted in the formation of compounds of indefinite compositions. Although literature is replete with examples of The analytical data of the schilT base complexes transition metal complexes of bis(acetylacetone)di- (Table 1) suggest that two molecules of hydrazine react amine ligands!" 5, relatively few complexes have been with one molecules of metal(ll) acetylacetonate. The reported with ligands derived from the condensation of analytical data also show the formation of 1: 2 addition acetylacetone wth only one end of the diamine":", The complexes with phenylhydrazine. While AcHz reactions of transition metal(II) acetylacetonates with complexes ofCo(II), Ni(II) and ZnOI) melt at 166',205 different chelating ligands containing at least one NH2 and 189'C respectively and are soluble in non-polar group have also been studied":". Recently, Datta and solvents like methanol, ethanol etc., all the coworkers!" have shown that the reactions of phenylhydrazine complexes melt with decomposition VO(acach with benzoylhydrazine .and related ligands above 250C and are insoluble in the above solvents. yield two types of schilT base complexes: one involving However, all the complexes are freely soluble in polar the condensation ofvanadyl oxygen and the other that solvents like DMF or DMSO. The molar conductance of the carbonyl oxygen of the acetylacetonate ring. No values of the complexes in DMF (10-3 M solutions) work appears to have been done on the reactions of fall in the range 3.76-8.42 mhos em? mol- I suggesting hydrazine and phenylhydrazine with metal(II) the non-ionic nature of all the complexes under acetylacetonates. A study of the reactions of the above discussion". The Il", values of CoOl) and Ni(I1) hydrazines with Co(ll), Ni(II) and Zn(ll) acetylaceto- complexes (4.98-5.02 and 3.04-3.10 B.M. respectively) nates was therefore undertaken and the results are consistent with spin-free octahedral geometry obtained are discussed in this note. around these metal ions I 5. All the chemicals used in the present work were An intense band in the region 31,250-31,746 ern I of BDH reagents or of equivalent grade. Hydrazine the UV spectra of M(AcHzh type complexes and a hydrate and phenylhydrazine were distilled twice band in the region 31,545-32,895 cm - I of the spectra of before use. Hydrated metal(l I) acetylacetonates were M(acach(PHzh type complexes is attributed to a 1[-1[* prepared as described in literature I I. Ex perimental transition due to the pscudoaromaticity of cnamine details pertaining to elemental analyses, molar and acetylacetonate ring respectively present in conductivity, magnetic susceptibility, electronic and IR them'2.'6 spectral studies were similar to those described in our The electronic spectra of Co(ll) complexes arc earlier paper 12 consistent with an octahedral stereochemistry as they AcHzH was prepared from the ice-cold ethanolic show two J-J bands at 8.772-9,346 and 18,519- solutions of hydrazine hydrate and acetylacetone 20,408cm I which can be assigned to 4T2y

1044 NOTES

Table I-Analytical, Magnetic and Electronic Spectral Data of the Complexes pc Compound Colour Found (Calc.), % Ileff. Dq B IJ LFSE I l (B.M.) (em -I) (cm- ) ( '/~) (kJmol- ) Metal N Co(AcHzh Pink 20.45 19.46 4.98 995.4 854.5 0.879 12.1 95.26 (20.68) (19.65) Cotacac), (PHzh Pinkish 12.21 11.58 5.02 1043.9 684.4 0.704 29.6 99.9 brown (12.46) (11.84) Ni(AcHzh Blue 20.21 19.43 3.10 985.2 932.8 0.896 10.4 141.42 (20.62) (19.67) Ni(acach(PHzh Greenish 12.33 11.63 3.04 995.0 806.1 0.774 22.6 142.83 blue (12.42) (11.85) Zn(AcHzh Greenish 22.04 18.98 white (22.44) (19.22) Zn(acach(PHzh Light 13.18 11.39 yellow (13.64) (11.68)

) complexes are assigned to perturbed carbonyl and (C..:...:..:. .-4TI9(F)(vl and 4T1g(P).-4T1g(F)(h) transitions respectively!" The spectra of Ni(II) complexes yield C)/(C..:...:..:.N)stretching vibrations respectively 16.1 9. The three d-d bands at 9,852-9,950, 15,980-16,130 and non-ligand bands obtained in the regions 430-410 and

22,270-23,510 cm - 1 assignable to the transitions 310-268 em -I in the spectra of M(AcHz}z and

arising from 3 Azg ground state to 3Tzg(v1), 3TI9(F)(vz) M(acac)z(PHz}z type complexes respectively are

and 3 T1g(P)(V3) excited states respectively. The assigned to v(M - 0) mode while those obtained in the positions and assignments of the banlis indicate region 258-227 cm - 1 in the spectra of all the complexes octahedral environment around the nickel(II)I? The under discussion are assigned to v(M - N) modezo.zl. p0 values of Co(ll) and Ni(II) complexes (Table1) References indicate maximum covalency of 12.1 and 29.6 percent 1 Holm R H, Everett (Jr) G W & Chakravorty A, Prog inorg Chern, in M(AcHz}z and phenylhydrazine complexes 7 (1966) 83. respectively. 2 Bong-II Kim, Chi Miyake & Imoto S,) inorg nucl Chern, 37 (1975) 963. The nujol mull spectrum of acetylacetonemono- 3 Biradar N S & Locker A L,) inorg nucl Chern, 37 (1975) 1308. hydrazone gives a broad band in the region 3500- 4 Rana V B. Singh P, Singh D P & Teotia M p, Polyhedron, 1 (1982) 377. 3000 em - 1 probably due to the presence of inter- and 5 Aggarwal R C & Surya Narayana D S, Indian) Chern, (accepted). intra-molecular hydrogen bonding between the OH 6 Wallis W N & Cummings S C, Inorg Chern, 13 (1974) 991. and NHjNHz groups of the ligand. Replacement of 7 Costes J P, Cross G, Donbien M H & Laurent J P, Inorg chim this broad band by two well-defined bands in the Acta, 60 (1982) 111. regions 3320-3310 and 3185-3180 ern - 1 in the spectra 8 Dey K, Maiti R K & Sen S K. Inorg chirn Acta. 20 (1976) 197. 9 Mathis A A D. Snow M R & Vanzo J A. Chern Cornrnun, 7 (1976) of its complexes suggests the presence of NHz group 264. and absence of OH group in the complexes. The v(N 10 Datta R L & Pal A K. Indian) Chern, 21A (1982) 1130. - N) band observed at 888 cm - 1 in the' spectrum of II Fackler (Jr) J P. Prog inorg Chern. 7 (1966) 361. acetylacetone monohydrazone is shifted to the region 12 Aggarwal R C, Surya Narayana D S & Sekhar V C, Indian) 980-958 em - 1 in the spectra of M(AcHzh complexes. A Chern. 21A (1982) 419. 13 Dornnin N A. Syui-Kun Van & Glcbovskaya N S. Zhur obsch 'positive shift of 70-92 ern - 1 in the above mode Khirn. 27 (1957) 1512: Chern Abstr. 52 (1957) 37014. provides a strong evidence for the bridging bidentate 14 Geary W J. Coord Chern Rt'l". 7 (1971) 81. nature of the N - N moiety of the ligand 1 B. 15 Cotton F A & Wilkinson G. Adranced inorganic Chemistry. Phenylhydrazine gives a broad band in the region (Wiley. New York) 1976.916. 34()()-3250 cm - I and a weak band at 3090 cm - 1 due to 16 Cumnings S C & Sievers R E.lnorg Chern. 9 (1970) 1131. NH/NHz groups and these bands are shifted to lower 17 Lever A B P. Inorganic electronic spectroscopy (Elsevier. frequencies (3390, 3195 and 3040 cm - I) in the Amsterdam) 1968. 324. 334. 18 Braibanti A. Dallawalle F. Pellingheli M A & Leaporathi E. complexes. indicating the coordination of phenyl- l norg Chem. 7 (1968) 1430. 1 hydrazinel'l. A positive shift of 40-49cm- in the \'(N 19 Heigh J M. Slabber! N P & Thornton D A.) molec Struct, 7 (1971) - N) band in the complexes as compared to its position 199. (Xn cm - I) in the ligand supports the un identate 20 Nakamoto K. Infrared and Raman spectra of Inorganic and coordination of the (N - N) moiety of phenyl- coordillation compollllds (Wiley Interscience. New York) 197X.p.199. 228. hydrazine/". The bands observed in the regions 1590- 21 Hoodson J B. Percy G C & Thornton D A. Transition Metal 1560 and 1515-14XOcm-1 in the spectra of all the ClJem. 3 (1978) 302.

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