Chemistry of dirhenium(II) and dimolybdenum(II) complexes containing sigma-donor, pi-acceptor and bridging ligands

The triply bonded complexes Re{dollar}sb2{dollar}X{dollar}sb4{dollar}(dppm){dollar}sb2{dollar} (X = Cl or Br; dppm = Ph{dollar}sb2{dollar}PCH{dollar}sb2{dollar}PPh{dollar}sb2{dollar}) react with tertiary phosphine and phosphite ligands to afford the 1:1 adducts Re{dollar}sb2{dollar}X{dollar}sb4{dollar}(dppm){dollar}sb2{dollar}(L) (L = PR{dollar}sb3{dollar} or P(OR){dollar}sb3{dollar}; R = Me, Et or Ph) which may have the A-frame-like structure X{dollar}sb2{dollar}Re({dollar}mu{dollar}-X) ({dollar}mu{dollar}-dppm){dollar}sb2{dollar}ReX(L). Re{dollar}sb2{dollar}Cl{dollar}sb4{dollar}(dppm){dollar}sb2{dollar}(PMe{dollar}sb3{dollar}) reacts with nitrile ligands R{dollar}spprime{dollar}CN (R{dollar}spprime{dollar} = Me, Et, Ph or CH{dollar}sb2{dollar}Ph) in the presence of TlPF{dollar}sb6{dollar} to yield the complexes (Re{dollar}sb2{dollar}Cl{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(NCR{dollar}spprime{dollar}){dollar}sb2{dollar}) PF{dollar}sb6{dollar}.; Reactions of Re{dollar}sb2{dollar}X{dollar}sb4{dollar}(dppm){dollar}sb2{dollar} with CO and R{dollar}sp{lcub}primeprime{rcub}{dollar}NC (R{dollar}sp{lcub}primeprime{rcub}{dollar} = Bu{dollar}sp{lcub}rm t{rcub}{dollar} or xylyl) give the complexes Re{dollar}sb2{dollar}X{dollar}sb4{dollar}(dppm){dollar}sb2{dollar}(CO){dollar}sb{lcub}rm n{rcub}{dollar} (n = 1 or 2) and Re{dollar}sb2{dollar}X{dollar}sb4{dollar}(dppm){dollar}sb2{dollar}(CO)(CNR{dollar}sp{lcub}primeprime{rcub}{dollar}), respectively. Re{dollar}sb2{dollar}X{dollar}sb4{dollar}(dppm){dollar}sb2{dollar}(CO) reacts with PR{dollar}sb3{dollar} and P(OR){dollar}sb3{dollar} to form the complexes (Re{dollar}sb2{dollar}X{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(CO)(PR{dollar}sb3{dollar}){dollar}sb2{dollar}) {dollar}sp+{dollar}(A){dollar}sp-{dollar} (A = Cl, BPh{dollar}sb4{dollar} or PF{dollar}sb6{dollar}) or {dollar}{lcub}{dollar}Re{dollar}sb2{dollar}X{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(CO)(P(OR){dollar}sb3{dollar}) {dollar}sb2{rcub}{dollar}PF{dollar}sb6{dollar}, whereas Re{dollar}sb2{dollar}X{dollar}sb4{dollar}(dppm){dollar}sb2{dollar}(CO)(CNR{dollar}sp{lcub}primeprime{rcub}{dollar}) reacts further with PR{dollar}sb3{dollar} in the presence of TlPF{dollar}sb6{dollar} to form the complexes (Re{dollar}sb2{dollar}X{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(CO)(CNR{dollar}sp{lcub}primeprime{rcub}{dollar})(PR{dollar}sb3{dollar})) PF{dollar}sb6{dollar}. Re{dollar}sb2{dollar}X{dollar}sb4{dollar}(dppm){dollar}sb2{dollar}(CO){dollar}sb2{dollar} reacts with PR{dollar}sb3{dollar} or P(OR){dollar}sb3{dollar} to form the unsymmetrical {dollar}mu{dollar}-CO complexes (Re{dollar}sb2{dollar}X{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(CO){dollar}sb2{dollar}(L)) PF{dollar}sb6{dollar} (L = PR{dollar}sb3{dollar} or P(OR){dollar}sb3{dollar}) in the presence of TlPF{dollar}sb6{dollar}. (Re{dollar}sb2{dollar}Cl{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(CO){dollar}sb2{dollar}(PMe{dollar}sb3{dollar})) PF{dollar}sb6{dollar} can be reduced by Cp{dollar}sb2{dollar}Co to yield a neutral paramagnetic species (Re{dollar}sb2{dollar}X{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(CO)(PMe{dollar}sb3{dollar}){dollar}sb2{dollar}) {dollar}sp0{dollar}. The complexes (Re{dollar}sb2{dollar}Cl{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(CO)(PMe{dollar}sb3{dollar}){dollar}sb2{dollar}) Cl {dollar}cdot{dollar} 1/2CH{dollar}sb2{dollar}Cl{dollar}sb2{dollar}, (Re{dollar}sb2{dollar}Cl{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(CO){dollar}sb2{dollar}(PMe{dollar}sb3{dollar})) PF{dollar}sb6{dollar} and {dollar}{lcub}{dollar}Re{dollar}sb2{dollar}Cl{dollar}sb3{dollar}(dppm){dollar}sb2{dollar}(CO){dollar}sb2{dollar}(P(OEt){dollar}sb3{dollar}) {dollar}{rcub}{dollar}PF{dollar}sb6{dollar} were characterized by X-ray crystallography.; Reactions of Re{dollar}sb2{dollar}X{dollar}sb4{dollar}(dppm){dollar}sb2{dollar} with neat CS{...