The reactivity of disulfides and thiols with two tungsten tris-carbonyl systems: Tungsten(tris-carbonyl)(1,10-phenanthroline)(proprionitrile) and tungsten(tris-carbonyl)(tri-isopropyl phosphine)

The complex W(CO){dollar}sb3{dollar}(phen)(EtCN) (phen = 1,10-phenanthroline) undergoes oxidative addition with disulfides (R = phenyl, benzyl, and methyl) to produce the 16-electron complexes W(CO){dollar}sb2{dollar}(phen)(SR){dollar}sb2{dollar}. The reactions proceed through 18-electron intermediates identified spectroscopically as coordinated disulfide complexes. A crystal structure of {dollar}rm W(CO)sb2(phen)(SPh)sb2{dollar} is presented. The complexes {dollar}rm W(CO)sb2(phen)(SR)sb2{dollar} undergo ligand addition and ligand substitution reactions. Under pressure of carbon monoxide they reversibly bind CO to yield the 18-electron species {dollar}rm W(CO)sb3{dollar}(phen)(SR){dollar}sb2{dollar}. Reaction of trimethyl phosphite with {dollar}rm W(CO)sb2(phen)(SPh)sb2{dollar} produces {dollar}rm W(CO)(phen)(SPh)sb2(P(OMe)sb3{dollar}) and a crystal structure of this complex was obtained. Carbon monoxide reversibly binds to {dollar}rm W(CO)sb2(phen)(SPh)sb2{dollar} however, weaker ligands such as pyridine, nitriles, THF and hydrogen do not bind. Sulfur dioxide reacts with {dollar}rm W(CO)sb2{dollar}(phen)(SPh){dollar}sb2{dollar} to yield {dollar}rm W(CO)(phen)(SPh)sb2(etasp2{dollar}-SO{dollar}sb2{dollar}), the first tungsten(II)-SO{dollar}sb2{dollar} complex reported. This complex spontaneously converts (t{dollar}sb{lcub}1over2{rcub}{dollar} = 18 hours) to W(O){dollar}sb2{dollar}(phen)(SPh){dollar}sb2{dollar} in solution. The crystal structures of both {dollar}rm W(CO)(phen)(SPh)sb2(etasp2{dollar}-SO{dollar}sb2{dollar}) and {dollar}rm W(O)sb2(phen)(SPh)sb2{dollar} are reported.; {dollar}rm W(CO)sb3{dollar}(phen)(EtCN) undergoes oxidative addition with thiophenol to form the 7-coordinate complex {dollar}rm W(CO)sb3{dollar}(phen)(H)(SPh). The reaction is fully reversible in the presence of strong ligands (CO) resulting in reductive elimination of the thiol. Reaction of W(CO){dollar}sb3{dollar}(phen)(EtCN) with the dithiol 3,4-dimercaptotoluene first produces the hydrido thiolato complex {dollar}rm W(CO)sb3(phen)(H)(SCsb6Hsb3(SH)CHsb3{dollar}), which slowly converts to the chelated dithiolate, {dollar}rm W(CO)sb2{dollar}(phen)(toluene-3,4-dithiolate) and the side product {dollar}rm W(CO)sb4{dollar}(phen). A quantitative one-step route to the chelated dithiolate is the thiol exchange reaction of {dollar}rm W(CO)sb2(phen)(SPh)sb2{dollar} with 3,4-dimercaptotoluene which results in the elimination of two molar equivalents of thiophenol. {dollar}rm W(CO)sb2(phen)(SCHsb2Ph)sb2{dollar} undergoes thiol exchange with PhSH to form {dollar}rm W(CO)sb2(phen)(SPh)sb2{dollar} and two molar equivalents PhCH{dollar}sb2{dollar}SH.; The complex {dollar}rm W(CO)sb3(Psp{lcub}i{rcub}Prsb3)sb2{dollar} undergoes oxidative addition with thiols to produce the hydrido thiolato complex {dollar}rm W(CO)sb3(Psp{lcub}i{rcub}Prsb3)sb2(SPh)(H){dollar} which is fully reversible in the presence of moderate strength ligands such as nitriles. {dollar}rm W(CO)sb3(Psp{lcub}i{rcub}Prsb3)sb2{dollar} reacts with HI to produce the analogous hydrido iodo complex, {dollar}rm W(CO)sb3(Psp{lcub}i{rcub}Prsb3)sb2(H)(I){dollar}. Reaction of {dollar}rm W(CO)sb3(Psp{lcub}i{rcub}Prsb3)sb2{dollar} with one-half equivalent of disulfides or iodine forms the 17-electron radical species, {dollar}rm {lcub}cdot{rcub}W(CO)sb3(Psp{lcub}i{rcub}Prsb3)sb2{dollar}(X)(X = I, SPh, SMe, S-benzyl, S-tolyl). Crystal structures of {dollar}rm W(CO)sb3(Psp{lcub}i{rcub}Prsb3)sb2(H)(I) and {lcub}cdot{rcub}W(CO)sb3(Psp{lcub}i{rcub}Prsb3)sb2(I){dollar} are reported. {dollar}rm W(CO)sb3(Psp{lcub}i{rcub}Prsb3)sb2(Hsb2{dollar}) hydrogenates PhSSPh to produce PhSH.