Chemistry of vinylidene complexes. XXV. Synthesis and reactions of binuclear µ-vinylidene RePt complexes containing phosphite ligands. Spectroscopic, structural and electrochemical study

Abstract

Reactions of Cp(CO)(2)Re=C=CHPh with Pt[P(OR)(3)](4) (R = Pr-i, Et, Ph) gave binuclear mu-vinylidene complexes Cp(CO)(2)RePt(mu-C=CHPWW(OR)(3)](2). Treatment of the previously synthesized Cp(CO)(2)Re(mu-C=CHPh)Pt(PPh3)(2) with triisopropylphosphite or triethylphosphite resulted in a stepwise substitution of PPh3 ligands, leading to the disubstituted Cp(CO)(2)RePt(mu-C=CHPh)[P(OR)(3)](2) and monosubstituted Cp(CO)(2)RePt(mu-C=CHPh)[P(OR)(3)] (PPh3) (R = Pr-i or Et) species, while no triphenylphosphine ligand substitution in the reaction with P(OPh)(3) occurs at all. The monosubstituted Cp(CO)(2)RePt(mu-C=CHPh)IP(OR)(3)](PPh3) (R = Pe(i), Et, Ph) species were also obtained by reacting Cp(CO)(2)Re=C=CHPh with mixed-ligand complexes Pt(PPh3)(3)L (L = P(OPi)(3), P(OEt)(3), P (OPh)(3)). Reactions of Cp(CO)(2)RePt(mu-C=CHPh)LL' = L' = P(OPri)(3), P(OEt)(3), P(OPh)(3); L = P(OPri)(3), P(OEt)(3), P(OPh)(3), L' = PPh3) with Co-2(CO)(9) yield tricarbonyl vinylidene species Cp(CO)(2)RePt(mu-C=CHPh)IP(OR)(3)](CO) (R = Pr-i, Et, Ph). The obtained compounds were characterized by IR and H-1, C-13, P-31 NMR spectroscopy. The molecular structures of Cp(CO)(2)RePt(mu-C=CHPh)[P(OPi)(3)](2), Cp(CO)(2)RePt(mu-C=CHPh)[P(OPri)(3)](PPh3) and Cp(CO)(2)RePt(mu-C=CHPh)[P(OPri)(3)](CO) were determined by X-ray diffraction study. The redox properties of the new complexes and their reactions of chemical oxidation were studied.