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Ol*4 SYNTHESIS AND
CHARACTERISATION OF
(f|-C5Me4Et)Ru(CO)?SH
BY
NANCY ELLEN NICHOLS
THESIS
for the
DECREE OF BACHELOR OF SCIENCE
IN
CHEMISTRY
College of Liberal Arte end Soienoea
University of Illinois
Urbanei Illinois
1986
% 1 1 1 I* Introduction Introduction I*
Catr : ytei o (JC^tRfC)3 C0)?3H (iJ-Cj^EtjRuf of Synthesis 1: . Chapter H . Chapter . Chapter References References ?t Reactions of (i^-Cji^EtjRufCO^SH (i^-Cji^EtjRufCO^SH of Reactions Figures Figures als iQ Tables eeecs References Experimental eut Disoussion Results iue Figures als Tables eeecs References xeietl Experimental eut ##26 Results iosin Disoussion AL O CONTENTS OF TABLE V ...... 5 ,...2
40 . 39 37 34 32 17 14 11 9 . 9 8 INTRODUCTION
Hydrodesulfurisation (HDS) is an important catalytic procaas used in tha purification of patrolaum products. [1,2] This procsss involves tha hydroganolysis of organosulfur compounds ss shown in tha equations below. [3]
RSH + Ha— _ » RH + HaS RSR + 2 Hg---- » 2RH ♦ Ha 8 R88R + 3Ha— *2RH + 2Ha&
Interestingly, it has been found that the types of compounds which have high HDS activity are transition metal sulfides. In addition, measurements of the catalytic activity of a series of transition metal sulfides have shown that the ability of a particular sulfide to catalyse the HOB reaction is related to the position of the transition metal in the periodic table. [4] In particular, studies indicate that first row transition metal sulfides are relatively inactive, while the seoond and third row transition metals show maximum activity with ruthenium and osmium. (SI The mechanism by which the hydrodesulfurisation reaction occurs is not fully understood, end extensive research has boon devoted to this area. Nany who have etudied the hydroganolysis of thiophene have proposed that tha mechanism involves two types of sites on the surface of the sulfided catalyst. The first is a coordination vacancy on the metal ion where the organosulfur compound may interact with the metal. The second type of sites are the surface sulfide ligands which have been proposed to react with B2 to form hydrosulfido ligands. Finally, it has been suggested that carbon-sulfur bond rupture and hydrogen atom transfer occurs between the species adsorbed on these sites. (3] The possibility that a metallothiol complex may be part of the HD6 mechanism has generated much interest in these types of compounds. Over the past decade, many of these N-SB complexes have been synthesised and the reactivity of the -SB ligand studied. Several of these will be discussed in the following paragraphs. Salts of N(C0)5
It reacts analogously with 2,4- dinitrophenyl acetate to again give lNeC(*0)8W(C0)5]- . M(CO)j(8B)- has also been found to reaot rapidly with ketones, in the presence of acid catalyst te give 3
thick*ton* complexes according to th* aquationt [6]
W(CO)5 (8H)- + R2O 0 + 2CP38O3H-- >W(CO)5(8-CR2) + H20 + CF3SO3-
Th* ft- -dithiol (/<.-HS)2Fe2(CO)g is another metallothiol which has b**n *xt*nslv*ly studied. This complex is prepared by 1- first reducing ^-S2)F*2(CO)( to th* [(y^-S2)P*2(CO)*! anion. This dianion can then be protonated with trifluoroaeetic acid to give (fK -B8)2P*2 (CO)g. What is interesting about this complex is that th* SB function adds to <*,fi unsaturated substrates as illustrated in th* equation below1 (7] 2
----- >(OC) 3P*2 > # (CO) 3 piperadin* (Y> C02CB3, C(0)CH3CW)
Molybdenum complexes with th* formulation [(CH3)nC3H3.n- Mo(8)(8H))2 n- 0,1,5 are noteworthy due to their catalytic properties. It haa been found that thea* complexes eatalys* the reduction of elemental sulfur to hydrogen sulfide at remarkably mild conditions (1-3 atm. l2, 75*0. These hydrosulfido complexes are also interesting in that they too roaet with unsaturated moleculest(3] 4
R
[N«nCpN0(«)8B]2 + RC-CR— ♦Ren ► CpNen ♦ Hj
R R R R
[MenCpNo(8 )88)2 + 2C«C > «*nC CpR«n
R R •kill other N-fl ooapounds that should bo aentionsd oro [ 1 The exaaples given above are Just a few of the aaay prepared K - M nonpouudi. Others include Rh(BB)(CO)(P(Cgls)i)2' CpNs(M) (CO)3, Cpv(M) (CO)), and (Na(M) (€0)4)2 •* are interesting in that they are prepared by the foraal insertion of 5 sulfur into s aotnl bydrid* bond. Soat aotsllothiols have boon siaply proporod by rooctions with SB- salts. Baaaplos ineludo (diphos)N(8H)2 (M« Mi, Pd) proporod froa (diphos)NCl2 and Na8H (13)l trano-(PtB(8B)(PBt3)2], synthosisod froa trans-(PtCl(B)- (PBt3)2) and NaBB [14] t M(CO)3D8H (M-Cr, No, W> D> bipy, phen) aado froa CyBgNCCOls, bipy or phen, and Na8B [15]» and CpMi- (PBuylSB, proporod froa [CpMi(PBu3)2)+Cl- and BaSB (16). Sovoral N-8B ooapounds have also boon proporod froa roactiona with 82*. A fow osaaplos of thoso ineludo Pt(Fh3P)2(M)2 aado froa roaetion of Pt(Ph3P)2Cl2 with B28 (17]1 (BhCl(B)- (88)(PPh3)2] • 2CB2CI2 aado froa BhCKPPhyh and B28 (ll]i IrCMBMBBMCO) (PPh3)2, aado froa XrCl(CO) (PPhy^ and B2B (II] I and [N(BB)L]B''h4 (L-PP3, N - Pe, Co, Mil L- np3, N> Co, Mil pps >tr is(2-diphsnylphospb inoethyl)phosphine, np3- trls(2-diphenylphosphinoethyl)aaine aado froa N(BP4)2' BIEEUKIfi tlj Nascoth, F.E. 1978, 22, 265. [2] Schuaan, S.C.i Shallt, H. Cat. Rsv. 1970, 1 , 245. 13] Duboia, M.R.i Van Dtrvaar, n .C.i Dubois, D.L.i Haltiwangar, R.C.i Millsr, W.X. J. Aaar. Chaa. Roe. 1980, M2, 7456-61. [4] Pscararo, T.A.i Chianslli, R.R. J. Catal. 1981, fij, 430. [5] Harris, S.i Chianslli, R.R. J. Cat. 1984, Jf, 400-12. [6] Gingsrich, R.G.N.i Angalici, R.J. j, , eh— . ana. 8«pt, 2, 1979, Ml, 5604, [7] Ssyfsrth, D. i Hsndsrson, R.s. J. orgaupggfcgl ■ ChtB» 1981, 21$, C34-C36. [8] Hulloar, V.i Vahrankaop, H. Chsai. Bar. 1977, 1M» 3810-6. [9] Rauohfuss, T.B.I Ruffing, C.J. J. Organoaatal. 1985, 1, [10] Rauohfuss, T.B.I luffing, C.J. J.Ornanoaatal. 1982, 1, 400-1. [11] Gaffnay, T.R.i Ibars, J.A. inoro. ch— . 1982, 21, 2857-59. [12] Danaar, H.i Fahlhaaaar, w.p.i Liu, a .t .i Thial, G.i Back, W. ChtBU-MX^ 19*2, Ml, 1682-93. [13] Sohaidt, N.i Hoffaann, G.G.i Hollar, R. Inoro. Chia. Acta 1979, 22, L19-L29* [14] Blaoklawa, I.N.i Bbsvorth, l.A.V.i Rankin, d .n .H.i Robartson, H.I. J. chnn. anfl. Dolton Trans. 1978, 7S3. [15] Bahrana, H.i Lindnar, I.i Lahnart, G. 1970, 22, 665-76. [16] Bato^l^^Mito^^jMfakaaoto^N.i Kasuyoshi, I. [17] Sohaidt, N.i Hoffaann, O.G. 1977, 12i, CS-C8. 7 [18] Nutting, A.M.j Boyle, P.j Pignolet, L, ippfg, Cbfgj 1984, 22, 44-8. [19] Midollinl, M. t Sacoonl, L. Inoro. Ch— . 1977, Ifi, 1518. SYXTHESIS OF ( -C5Me4Bt)Ru«50)?SH imfiOSCXifitf As described preciously metal-SH complexes have become quite important in inorganic chemistry. This chapter describee the synthesis and characterisation of a new M-BH complex ty-Cglle^t) Ru (CO) 28B. 6 9 atatiLTfl Anhydrous aodiua hydrogen sulfide, • whit* hygroscopic powder, wee prepared in 76.21 yield frow sodiua ethoaide and hydrogen sulfide, using ethanol as a solvent. The aethod used was that described by Bibeck in Inaigwic. fttnttt— 111. MaSB is readily hydrolysed in aoist air to sodiua hydroxide and hydrogen sulfide. Xt can, however, be handled in air for short periods of tiae. To prevent decoaposition, the MaSB synthesised was stored in a vacuus dessieator. in this way, saaples were found to be stable for several weeks. The rutheniua hydrosulfido maples, (tl-CgNeiltJIUHCOlgMr was prepared by a aetathesis reaction between MaSI and ty~Cglle4> Bt)Ru(C0)2Br. By siaply slurrying a 30-fold excess of Ball with (t[-Cglle4Bt)ltu(CO)2Br in methanol , C^-CsNe4Bt)lt)Ru- (CO)2*1 was foraed in 74% yield. ty'CgllegBtlRu (CO) gBr + excess Ba*B-*(>'|-C5lle4lt)«u (CO) 2*1 +BaBr The new ceapound was isolated as an orange-brown seaicrystalline solid by evaporating off the aethanol, extracting the product with diohloroaethaae, filtering this solution through *1-2 bio-beads, and than evaporating off the dichloroawthane. ty-CgB04*t)Bu(CO)2*B is slightly air-sensitive and should bo stored under Bg or in ’SCUO . 10 The 1B mot spaetrua of this couplex was taksn using a GI QB-300 FT mot speetroaeter. This spaetrua is shown in figure 1. Observed were two singlats at 1.90 and 1.92 ppa assignad as tha tha four aathyl aubstituants on tha eyelopantadianyl ring. A quartat and a triplat eantarad at 2.32 ppa and 1.04 ppa raspaotivaly ara assignad to tha athyl substituant. Finally, tha thiol proton rasonanea is looatad at -2.79 ppa. This data is listad in Tabla 1. Resonances for othar aatallothiol protons occur -4.C7 ppa as in ((FhjFlgB]- (Cr(CO)sM]) -3.30 ppa as in ((FhjFlaRHNoCCOlaM]» and -2.93 ppa as in [(PhsFlaR) (N(CO)5SR] [2]. A solution » spaetrua of (ri-Cjl^Rt) Ru (CO) 28H in 1,2 dlchloroathana rawaalad two CO strotchas at 2010 and 1905 ca* (figura 2). A fiald desorption aass spaetrua of (iJ-CsReilt)Ru(CO)2 AH yielded a cluster of peaks froa 334 to 343 (figura 3). Tha highest peak, occurring at 340, is the aolaeular weight calculated for ty-Cslle4Bt)Ru(CO)2>R using tha atoale weights of tha aast coaaon isotopes of ruthaniua, carbon, oxygen, sulfur, and hydrogen. Zn addition, tha aass spaetrua of (vj-CsNsaBt)Ru(CO)2BB was siaulatad on a eoaputer and peak pareantagas given wara vary close to these obtained by calculations using the actual aass spaetrua. Siaulatad and calculated values ara ooapared in Tabla 2. 11 D ia s a n im (r)-CsN*4lt)Ru(CO)2S8 mi first isolated in an attaapt to •aka (ty-C5Na4lt)itu(CO)2]2Q*-’8)« Dr• Daaian Rodgers, of tbo Dnivarsity ofIllinois# was abia to ayntbaaiaa this aulfur bridgad rutbaniua dinar by raaotion of (>J-C5Ra4*t)Ru(CO)jBr with axoaaa N02S 9820 in aotbanol. Ha idantifiad tbia ooaplas by fiald daaorption aaaa spactroaatry, nuolaar aagnatie raaonanoa spactroaatry# and aieroanalyaia [2]. In an attaapt vaa aada to duplicata Dr. Rodger's results# orange-red oryatala vara isolatad in 10« yiald vbiob vara orignally thought to ba tba aulfur bridgad rutbaniua dlaar. Thu *H HRR apaetrua of tba oryatala# however, ahovad paaka with diffaraat ebaaioal abifta than for tba aulfur bridgad dlaar. Also# an additional paak was obsarvad at -2.79 ppa . Indaad, it vaa this paak at -2.79 ppa which indieatad that a rutbaniua thiol ooaplas bad poaaibly foraad. Thiol coaplaxaa of ebroaiua# aolybdanua# and tungsten have bean prepared (((fhjPlgl]IN(CO)588], M« Cr# No, N) and in tba MNR of aaeh# the thiol proton raaonanoa is found upfield of TNI. for tba ebroaiua ooaplas# the thiol proton raaonanoa is found at -4.17 ppai for tba aolybdanua oaaplax# at -3.39 ppaj and far tba tungsten ooaplas at -2.93 ppa (3). This data indeed supported the hypothesis of tba forantloa of tba thiol oaaplax. Tba nest atop was to aaasura a fiald desorption aaaa apaetrua of tbo oryatala. A eloaa apaetrua vaa obtained vbiob shoved a cluster 12 of peaks from 334 to 343 H/x with the highest peak at 340, the molecular weight calculated for ty-C5Me4Bt)Ru(CO)2SH using the atomic weights of the most common isotopes of ruthenium, sulfur, carbon, oxygen, and hydrogen. Finally, the crystals were submitted for microanalysis. The ealulated and observed percentages of carbon and hydrogen (Calc, C, 4(.02| H, 5.30. Poundt C, 45.68) H, 5.18) are fairly close. Reasons for the discrepencies could include the fact that ruthenium thiol complex is slightly air sensitive. Having isolated ty-C5Me4Et)Ru(CO)28H, preparation of thla complex via another route was attempted in order to obtain a higher yield. Thia alternate route consisted of dissolving (rf-CsMea- Kt)Ru(CO)2Br in methanol, adding an equivalent of triethylamine, and bubbling H28 through the solution. This attempt, however, was unsuccessful as little or no reaction occurred. Because other transition metal hydrosulfido complexes have been prepared by reaction with 8H- salts, it was thought that perhaps such a reaction between Na8H and (f{->C5Ne4Bt)Ru(CO)2Br would produce the desired thiol complex |4J—[71. As described previously, this synthesis was indeed successful, A bit more can be said about (q-CglleaEtlRufCOgEB. The oomplex has a *piano-stool* like structure as shown in figure 4. A plane of symmetry passes through the ethyl substituent on the Cp ring, through the ruthenium canter, and through the thiol substituent. 13 Upon exposure to air for several days, orange-brown (^-Cgt^EtlRufCOJgSB turned to a dark brown color, it is possible that in air (7~C5Me4Bt)Ru(CO)2SB is converted to (^-C5Ne4Bt)Ru(CO)]2 (/u ’8H)2« Evidence for this hypothesis can be obtained from others' observations on (r}-C5B5)Ru(CO)2SMe, prepared by uv irradiation of a solution of [(TI-C5B5)- Ru(CO)2l2 with an excess of 62X02 (8]. It has been found that ty-C5H5)Ru(CO)2SMe slowly dimerises in the solid state at room temperature to form ((*l~C5B5)Ru(CO)8ile)2 which consists of six isomeric forms shown in figure 5. It has also been found that heating or irradiating solutions of (^-C5Bs)Ru(CO)28Ne produces the diruthenium complex [8]. In comparing the properties of (i}-C5MS4Bt)Ru(00)288 with the starting material (i{-C5Me4St)Ru(CO)2Br, both similarities and differences were found. Both were observed to be soluble in methanol, ethanol, acetone, and dichlorosethane, but insoluble in hexane. In comparing TLC stabilites, however, these compounds were found to be quite different. (f|-CsNe4Bt)Ru(CO)2Br moved cleanly on a TLC plate (Rf value* 0.68 in CB2CI2) while (*[-C5Ne4Et)Ru(CO)28B appeared to decompose on the plate. Also, (*lrCsNC4Bt)Ru(CO)28B was observed to be air sensitive, possibly converting to [ p|~C5Ne4Et)Ru(CO) )g (f—BH)j *n the presenoe of Og, while ty-CgJle4Bt)Ru(CO)2Br wee found to be steble in sir indsfinitely. 14 HSEUflUffAI' Absolut* *thsnol was obtained fro* 0.8. industrial Chanleals Co.i H28 was obtained fro* Air Products Inc.» and absolute nethanol and anhydrous ethyl ether were purchased fro* Baker. (72-C5M*4Et)Ru- (CO)jBr was supplied by a member of the Rauchfuss Research Group and was prepared by a method described by Baines and DuPrees [9]. All reagents listed above were used without further purification. Proton NNR's were recorded at 300 MBs on a G8 QE 300 FT-NHR spectrometer. IR spectra were recorded on a Perkin-Elner 487 grating Infra-Red Spectrometer, and field desorption mass spectra were measured on a Varian 731 Spectrometer at the University of Illinois Hass Spectrometry Lab. Microanalyses were performed by the School of Chemical Sciences Microanalytieal Laboratory. BaSB [1] 1 An oven dried 300 ml three-necked flask was fitted with a condenser, two glass stoppers, and a stirbac. Approximately 70 *1 of Ng-saturated, dry, absolute ethanol were added to the flask. 3g of Ha (.1305 moles) were weighed out and cut into small pieces. The small pieces were quickly added to the ethanol, and a reaction between Ha and ethanol began immediately. After the sodium had completely dissolved, BgS was bubbled through the reaction mixture for about two hours at the rate of about five bubbles/second. After about 30 minutes, a small amount of BaSB precipitated out as a 15 whit* solid. A* th* reaction proceeded, nor* NaSB precipitated. After two houra, th* reaction nixtur* waa transferred to a SOO nl Erlenneyer flask, and th* rest of th* NaSH was precipitated out with about 200 nl of anhydrous ethyl ether. Th* whit* precipitate was filtered using a glass frit and then stored in a vaeuun desslcator. Yields 5.57 g (.0994 moles) 76.21. iQzCSfttjIlLBJliCflljJflt An oven dried 50 nl Schlenk flask was connected to a Schlenk line and while hot was alternately evacuated and filled with three tines. Against a flow of N2, 0.513 g (0.00132 moles) of (^-C5N*4Bt)Ru(CO)2Br were added to th* flask along with a stir bar. Th* flask was then evacuated and filled with M2 three nor* tines. Approximately 15 ml of degassed nethanol were added via cannula, and th* (Tj-CgN*^ Kt)ftu(CO)2Br was allowed to dissolve. Against a flow of N2 an excess of HaSH was added (2.91 g, 0.0519 noles) and th* reaction nixtur* was stirred under N2 for about on* week. During this tine, the color of th* reaction nixtur* went fron yellow to orange. Th* conpletion of th* reaction was confirned by the disappearance of a yellow spot, identified as (if-€5ll*4Rt)Ru(CO)2Br, on a TLC plat*. Th* work-up of (^-C5N«4Bt)Xu(CO)2SH entailed several steps. Pirst, nethanol was removed by pulling a vacuum on th* reaction vassal and condensing th* methanol into a liquid N2 cooled trap, the orange solid left behind oenaistad of 16 ty-C$lt*4Bt)ltu(CO)2SH and unreacted NaSH. Approximately 20 ml of degassed CH2CI2 ware added to the orange solid to extract the (f}>CgNe4Et)llu(CO)2SH. After a few minutes of stirring, the orange solution was separated from insoluble NaSH by filtering through a filter cannula into another 50 ml schlenck flask. Cannula filtration however was not sufficient to totally separate NaSH from the desired product as a small amountof a very fine white precipitate was found in the orange solution after filtration. This residual NaSH was successfully removed by filtration of the product through a 1-1.5 inch plug of S-X2 bio-beads. The filtrate was then placed in a round bottom flask, and CH2CI2 was removed by rotary evaporation. An orange brown oil was left behind which solidified after minutes on a vacuum line. Yields 0.333 g (0.9815 mmoles), 74%. 1B NNR (CDCI3, TH8)t £ 2.32 (q, CB2CB3) 1.90 (s, CH3); 1.92 (s, CH3)| 1.04 (t, CH2Cfl3)» -2.79 (s, SB). IRs tfC0* 2010 cm* , 1965 cm1. 17 UtIUKIS [1] Eibeck, R.E. lDfiXfl*-5XHtlU 1963, J, 128. [2] Rauchfuss, T.B.I Rodgers, D. unpublished rssults [3] Gingerich, R.G.W.> Angelici, R.J. J. Ansi. ChH»f gpc« 1979, M l, 5604. [4] Schmidt, M.j Hoffmann, G.G.i Hollar, R. Inorg. ghlm. fpfcp 1979, 22, L19-L20. [5] Blaeklaws, x.M.i Egsworth, E.A.v.j Rankin, D.H.H.> Robertson, H.E. 1978, 753. [6] Sato, H.i Sato, S.i Takamoto, N.t Kasuyoahi, I. 1972, 2J. [7] Behrens, H.» Lindner, E.j Lahnart, G. J. Orgenometel. phfff, 1970, 22, 565-76. [8] Killops, S.D.i Knox, S.A.R. J. Chan. Soe. Dalton Trane. 1978, 1260. [9] Haines, A.L.i du Press TlMSe 1972, 944. 18 Table 1 _$L &Ba-at-isastD*Ds* PXfl&lU-XMSSJUiblP.XfiX.XMfiJWaSt 1.04 triplet CH2Cfl3 1.90 singlet CH3 1.92 singlet ch3 2.32 quartet CB2CH3 ISO 2010 cnl 19(5 can* 19 Table 2 Comparison of simulated and calculated peak percentages K/z simulated peak percentages calculated peak percentages 334 4.5057 4.65 335 .6969 1.55 336 1.7978 2.32 337 10.6724 9.69 338 12.0227 10.46 339 16.1867 18.60 340 28.7030 28.68 341 4.9160 4.65 342 16.8487 16.27 343 2.5574 3.10 CcmpsrtMC of SlmutsUd «nd lupsrtmwtsl Us m Spsdrum J J .■ lkUW!Vf.lliUUIILi|lllll Z1 Figure 1 : 1H NMR spectrum of (1| - CjM e^Et) Ru ( CO) 2 SH Figure 2: IB spectra of (n-C5Me4Et)Ru(C0 )2 SH iMmiliri i «1M ii 23 Figure 3< Mate apeetrum of («-C5Me4Et)Ru(CO)2SH ?4 F ig u r e 4 : fy - C 5Me4Et)Ru(CO)2SH Figure 5» isomers of (ty-C5tfe4Et)Ru(CO)SMe)2 (ER- SMe) CHAPTER TWO REACTIONS OP (Jl-CjM^EtjRut CO)SH IMTMDOCTIOH The previous ehaptsr described the synthesis of s new K-SH ooaples. This section describes the resotions etteapted using (i^-CjMesIt) Ru (CO) gSH. 25 26 I f i O U M Several different experiments ware performed with (^-CsMea- Et)Ru(CO)2SH, specifically, experiments to determine the properties of the -SH ligand. The first experiment was an attempt to observe the formation of (»|- C5Ne4Et)Ru(CO)2SL>. A few milligrams of (f^-CjNiStlRu- (COljSB were placed in an NMR tube and dissolved with CDCI3 and an NMR spectrum was recorded (figure 1). The tube was then removed from the probe and to it was added two-three drops of DjO. The tube was shaken vigorously for a few minutes and placed back in the probe. Another NMR spectrum was taken, and as can be seen from figure 2, the singlet at -2.79 ppm, corresponding to the thiol proton, nearly diosppesrod indicating the formation of ^ “Cgftea- Et)Ru(C0)2«D. (^-CsNe4Et)Ru(CO)28H + excess D20-*(l[-C5Me4lt)Ru(CO)2SD The next set of experiments performed were attempts to make a Ru-I-N complex where NaNo,Ru. One equivalent of (^-CjMsgStlRu- (CO)2>l was treated with oae equivalent of triethylamine and one equivalent of (Cgl4Na)No(CO)3Cl in TNT. The reaction was performed under N2 and was allowed to stir for three days. A TLC waa taken a few hours after the reaction was begun, and the faint appearanoe of a new spot indicated that perhaps a reaction was oeourring. Over the course of the three days, however, the intensity 27 of the spot did not change. Also to ba notad was tha appasranca of a dark brown praclpitata aftar about a day. At tha and of thraa days, anothar TLC lndicatad that thara was still starting material prasant. Tha brown praclpitata was filtarad off and THF was removed from tha filtrata via rotary avaporation. A rad-brown oil was laft bahind. Tha oil was dissolvad in CDCI3 and and NMR spactrum was takan. A vary complax spactrum was obtained, and no avidanca for tha dasirad product was found. It did seem, however, that both starting satarials had daconposad to a cartain dagraa. In tha absanca of ramotion, this dacomposltion of starting matarials was axpactad owing to tha instability of both 0f-CsMa4lt)ltu(CO)2*> and (i|—C9H4 Na)No(CO)jCl in tha prasanea ef triathylamina for axtandad pariods of tins, as determined by indapandant experiments. Tha sana typa of raaetion was attaaptad using ona aguivalant of (i^-CgMglt)Ru(CO)yRr in plaoa of tha nolybdanua compound. This raaetion was stirrad for 2-3 days, and during this tins, thara was no indication of a raaetion. Thara wara no naw products by TLC, nor did tha spot idantifiad as ty-CsM^ltlRutCO^Rr diminish. Also, tha raaetion mixture did not changs color as it should havs if (Cf-CgMa4lt)Ru(CO)2]i (jt-S), known to hava a raddish-brawn color, had formad [1 ]. Being unsuccessful with forming bimetallic complexes from 0t-C3MS4lt)Ru(CO)28H, a naw, simple type of reaction was attempted. Ona aguivalant of (i£-C3R#4rt)Ru(CO)28H was reacted with one-half aguivalant of iodine and ona aguivalant of 28 triethylamina with the idea of making a Ru-S-Ru or Ru-S-S-Ru complex. The product of the above reaction waa isolated as orange-red air stable microcrystals, which were characterised by NMR, IR, microanalysis, and mass spectrometry. The NMR spectrum (figure 3) showed a multiplet, or actually two overlapping triplets, at 1.12 ppm» a pair of singlets at 1.92 and 1.94 ppm, another pair of singlets at 1.97 and 1.98 ppmr and another multiplet, actually two overlapping quartets, at 2.33 ppm. This spectrum indicated the presence of either equal amounts of two different ruthenium compounds or one unsymmetric compound containing two types of cyclopentadienyl ligands. A solution I.R. spectrum was recorded of the crystals in 1,2-dichloroethane (figure 4). Terminal co absorptions were observed at 2044, 2022, 1990, and 197S cm*, interestingly, (i£-CjMe4!t)Ru(CO)21 has CO stretches at 2020 and 197S cm1*, indicating that it could have been one of the products of the reaction. The field desorption mass spectrum was also rather curious, teens taken at 14 mA and 1C aA gave spectra with a cluster of peaks centered arottnd 434 N/s. The highest peak, occurring at 434, is the molecular weight calculated for ty-C5Me4Bt)Ru(CO)2X using the atomic weights of the most common isotopes of ruthenium, carbon, oxygen, hydrogen, and iodine, in addition, the mass spectrum of M-CsNe4tt)Ru(CO)2l was simulated on a computer and peak 29 percentages given were very close to those obtained by calculations / using the actual mesa spectrum. Simulated and calculated values are compared in Table 1. Again, this data tends to indicate that (<(»CjMe4fct)ilu(CO)2l could have been one of the products o£ the reaction, in the last scan taken at 22 mA, small clusters of peaks occurred from 366-373 N/s, from 397-406 N/x, from 428-438 M/s, from 700-710 N/s, and from 833-848 N/s. The most significant cluster occurred from 800-818 N/s. It was thought that this large cluster might correspond to [(^-CgNe4Bt)Ru(CO)]2 (^-I)2 whose molecular weight, calculated using the atomic weights of the most common isotopes of carbon, hydrogen, ruthenium, oxygen, and iodine, was found to be 812. The computer simlated mess spectrum of [(l)-CsHe4Bt)Ru(CO) Ig (/^I>2» however, did not correlate extremely well with the actual one as shown in table 2. A microanalysis was also performed on this isolated compound. The percentage of carbon was found to be 34.97 while the percentage of hydrogen was found to be 3.90. For (TI-CjNeaBt)Ru(CO)21, % carbon equals 36.05 and IH equals 3.92, and for (ty-CsNsgBt)- Ru(CO)l2(H"l)2» * carbon equals 35.58 and « hydrogan equals 4.20. it is oonceivable, than, baaed on this and IR, MNR, and mass spectrum data that the product isolated was actually a mixture of (i)-C|N04Bt)Ru(CO)2X and l(7-C5Ne4tt)Ru(CO)(^-I>2• Problems with this formulation include the fact that in the NNR spectrum the pair of singlets at 1.97 and 1.98 ppm are slightly ahiftad from the pair of singlats in the NNR spectrum of authentic 30 (»-C5N«4Bt)Ru(CO)2l which occur at 2.07 and 2.08. Alao as mentioned before, the simulated mass spectrum of [M-CsMeaEtlRu- (co)]j(^.-1)2 does not agree perfectly with the experimental mass spectrum. Another Important observation is that in the mass spectrum taken at 22 mA, the smaller clustets from 386-373 M/s, from 397-406 M/s, and from 428-438 M/s are separated from one another by approximately 32 M/s. Similarly, the clusters from 800-818 N/s, and from 833-848 M/s are also separated by approximately 32 N/s. This data may indeed indicate the presence of a sulfur-containing compound rather than (q'C5Me4Bt)Ru(CO)2l and l (if-C3Me4Bt)Ru(CO) l2(*-I)2. Experiments which could be performed to reveal the true Identity of the compound include preparing a sufficient amount of the crystals for sulfur and iodine microanalysis and submitting the crystals for a crystal structure determination. The compound crystallised very nicly from hexane/l,2-dichloroethane. This solvent could probably be used to grow x-ray quality crystals. Still another series of experiments performed with (n-CgMea- St)Ru(CO)2SH involved attempts to make compounds such as -C|MS4Bt)Xu (CO) 2SR (R- Me, Bt). When («l-C|Me4St)Ru- CO)2>l was reacted, under >2, with one equivalent of triethyl M i n a and two equivalents of methyl iodide, in TRf, Pf-CsNegBt)- Ru (CO)2I was formed rather than the expeeted p|-CgNealtlRu- (CO)2She. The propeaed pathway for the formation ofH-C|Ne4- St)Ru(CO)2l is the followings 31 (^-C5«t4Et)Ru(CO)2SH— * (^-C5M«4Et)Ru(CO)2SMe — * (^-C5M4lt)Ru(CO)28PI#2— >» ( -C5M#4Et)Ru(CO)2I + SMe2 The whltt precipitate that was obaerved was probably ItjHH+l-. Whan on# equivalent of (r{-C5lle4Et)Ru(CO)2SH waa reacted, undtr Nj, with ona equivalent of athyl bromide and ona equivalent of triethylamina, in fJ-Cjl^EORufCOJjgEt waa not forated aa determined from tha IMR and IR apactra. 3? DI8C088I0N Th« purpose of this Motion is to discuss the properties of («2>C5Ne4lt)Ru(CO)28H end hence atteapt to explain why it behaves as it does in the previously described reactions. Sulfur containing ligands are interesting in that because sulfur has eaipty 3d orbitals, it can receive electron density froa a natal to which it is bonded. Such is the case with the sulfur in the -8H ligand in (^-CjNe^t) Xu (CO) 28H. This sulfur receives electron density froa the rutheniua center, and can thus be described as electron rich. This property of being electron rich iaplies that the sulfur atoa is destabilised in the foraation of ty-Cgl^Itlltu- (C0)2S- and thus that the -8H ligand is not acidic. The electron rich property of the sulfur in the thiol ligand aay indeed explain the aeohanisa by which (*}»C5Me4Rt)Ru(CO)2Sp was foraed when a few drops of DgO were added to an MMX saaple of ty-CsNegStlRufCOlgSR. Perhaps the aeohanisa is as follows! (7-CsN«4>t)ftu(C0).*l-- * Pg-C4l.4Bt)lt.(CO)2fB'-- 0 — D \V / Because of the non-aoidic nature of the -SB group, the unsuooessful atteapt at aafcing Ru-8-M ooaplexes (N ■ No, Ru) by reacting (^-C$Me4Rt)Ru(CO)2BB with trlathylaaine and (^'•CgKe4B)Mo(CO)3Cl or (^-CsMegBt) Ru (CO) gBr, was possibly 33 due to the fact that the (q-C5Me4Et)Ru(CO)2S- apaclaa was navac foraed. Perhaps if a stronger bass had bean used, this (^'CgNa^ Et)Ru(CO)28- spaeias sight hava bean generated. Also, sons different reaction oonditions should have been atteapted such as heating the reaction aixture. Since I- is a better leaving group than Br-, perhaps reaction between ty-CsI^Bt)Ru(CO) 28H and M-CsMeiBt)Ru(CO)21 would have produced a sulfur bridged diaer. The electron rich nature of the sulfur atoa also tends to support the reaction pathway, described in the results section for the the foraation of (^-Cg^BtJRutCOlgl froa (’J-CsJ^Et)- (00)288 and CH3I, The electron rich sulfur allows the foraation of (?-C2N*48fc)*u(CO)2SNo2. Because I- is a good nucleophile and SMeg a good leaving group, Pl-Cg^ltlRufCOJgX was consequently foraed. Perhaps if only one equivalent of CH3I had been used, the desired aethyl derivative would have been isolated. Also, it seeas rather curious that when (’|-Cslle4lt)Ru(CO)2SH was aised with triethylaaine and ethyl broaide, ty-C$lle4Bt)Ru- (COIjSIt was not foraed. Perhaps this is because broaide is not as good a leaving group as iodide. r 34 BgBMHlBIM. Iodine was purchased from Mallinckrodtf nethyl iodide was obtained froc Aldrich. Both of these reagents were used without further purification. Triethyla*ins was obtained fron a Dauber of the Rauehfuse Reaeearch Group, and THP, purchased from Aldrich was distilled over CaHy. Proton MMR spectra were recorded at 300 NHs using a GB QI-300 FT NNR spectroneter. IR spectra were run on a Ferkin-Blner 467 grating Infra-Red Spectroneter, and field desorption ease spectra were neesured on a varian 731 Spectroneter at the University of Illinois Hass Spectronetry Lab. Nicroanelyaee were perforated by the School of Chenical Sciences Hieroanalytical Laboratory. UlBfciOILflf. H a fifjBfciBsICQlalj. Mltfc. MlCijCtjlj *ad_Ia* 0.035 g of (^-C|NS4lt)Ru(CO)2SB (0.1032 nnole) were pieced in a 25 nl round botten flask along with a stirbar. About 10 nl of thf were added to the flask to dissolve the ( -CjNeeBt)Ru(CO)y, giving a yellow-orange solution. 14.4/al of NfClgCByls (0.103 nnole) were then added followed by the addition of 0.0131 g (0.0516 moles) of ly. The reaction nistur'e turned red, and was then allowed to stir for 30 nlaufees. Mo additional color changes took place. After the given tine, the flask was placed on the rotory evaporator and TBP was renewed, leaving behind a red-orange oil. The oil was washed with two 20 nl portions of oi water. As a result of the washings, the oil solidified a 35 slight Mount. Upon tbs addition of about 15 al of anhydrous athyl athar, however, complete solidification took placa to yiald an oranga-rad solid which was consequently filtered off and than recrystallised fro* dichloroaethane/ethar. 9.6 ng of oranga-rad microcrystals ware isolated. The absolute identity of this compound has not bean determined, but spectroscopic data has bean obtained. 1h NMh (CDCl3,TM8) (s 1.12 (■)* 1.92 (s)| 1.94 (s)| 1.97 (a)| 1.98 (s)f 2.33 (a). IRi ?co‘ 2044 ca'1, 2022 ca*, 1990 cal, 1975 ca1. .i Founds C, 34.97» H, 3.90. la^ctlon of (q-CjMajafcta^fcotjgM with MtcijCBjlj ABdLfiljii An owan baked 10 al Schlenk flaak was connected to a Bchlenk line while hot and alternately evacuated and filled with Da three tiaes. Against a flow of Ng, 14.3 ag of («J-C51104- Bt)Ru(CO)gSR (0.0422 aoles) were placed in the flask. The flask wss then evacuated and purged with Mg three additional tiaes. Approximately 3 al of dry nr ware syringed in followed by 5.9^1 of MCNgCN))) (0.0422 aaolss) and 5.24 j*.1 of CH3I (0.0844 ■aoles). After sirring for about 10 ainutes , the yellow-orange # solution turned Intensely orange and a whits proolpltsto started to fora. The reaction mixture was allowed to stir for an additional 10 ainutes. After that time, nr was removed and condensed into an Ng cooled trap. The orange solid loft behind was washed twice with 5 ml portions of DX water, and then puapod on. MB and IN spectra 36 confirmd tha product formd was (i£-CjM«4Bt)Ru(CC]£l. 1h NMR« (TUB, CDC13) S 2.38 RKFKBfUfyg [11 Rauchfuas, T.B. i Rodgara, D. unpubliahad raaulta. Table 1 Comparison of simulated and calculated peak >ercentages ajmulated peak peroantaflea calculated peak 3ere.nt.p., Usa 4.74 4.1? 4?9 .6956 .73 430 1 .676: 1.70 431 11.1698 10.91 43? i? .4915 12.1? 433 16.4416 18.30 434 29.5275 "8.73 435 4.2082 4.36 436 16.3901 16.1? 437 2.3739 2.6? 438 .2259 .24 3 Table 2 Comparison of aimvlatad and calculated peak percentages h h simulated peak percentages calculated peak percentages .2311 .6 800 .0624 1.5 801 .1659 1 .1 802 1.1105 2.5 803 1.3799 2.4 804 2.1298 3.8 805 4.7745 3*9 806 4.1512 7.0 80? 7-9422 7.3 808 11.4190 9.1 809 11.6469 11.8 810 14.5934 8.5 811 14.7530 12.1 812 8.3483 7.5 813 10.7338 7.2 814 2.6529 3.7 815 3.0006 4.2 816 .7474 2.6 817 .1056 1.3 818 tempHsm (ffimiiM tntf iNptHmiiiltl flM Sptdniii 16 I 40 Figure 1: 1H NMR spectrum of 0»-C5Me4Et)Ru(CO)2SH *T « Figure 2 s ty-C5Me4Et)Ru(CO)2SH + DgO 42 Figure 3: (»|-C5Me4Et)Ru(C0)2SH + I2 + EtjN M{»3 ♦ h ♦ HS2(00)nH(«V<5o-i) :> wnSTi £t