Synthesis and electrochemistry of heterobimetallic ruthenium/platinum and molybdenum/platinum complexes

As starting materials for heterobimetallic complexes, [RuCp(PPh(3))CO(PPh(2)H)]PF6 and [RuCp(PPh(3))CO(eta(1)-dppm)]PF6 were prepared from RuCp(PPh(3))(CO)Cl. In the course of preparing [RuCp(eta(2)-dppm)(eta(1)-dppm)]Cl from RuCp(Ph(3)P)(eta(1)-dppm)Cl, the new monomer RuCpCl(eta(1)-dppm)(2) was isolated. The uncommon coordination mode of the two monodentate bis(phosphines) was confirmed by X-ray crystallography [a = 11.490(1) Angstrom, b = 14.869(2) Angstrom, c = 15.447(2) Angstrom, alpha = 84.63(1)degrees, beta = 70.55(1)degrees, gamma = 72.92(1)degrees, V = 2378.7(5) Angstrom(3), d(calc) = 1.355 g cm(-3) (298 K), triclinic, P (1) over bar, Z = 2]. The dppm-bridged bimetallic complexes RuCp(PPh(3))Cl(mu-dppm)PtCl2, RuCpCl(mu-dppm)(2)PtCl2, and [RuCp(PPh(3))CO(mu-dppm)PtCl2]PF6 each exhibit electrochemistry consistent with varying degrees of metal-metal interaction. The cationic heterobimetallic complexes [Mo(CO)3(mu-dppm)(2)Pt(H)]PF6 and [MoCp(Co)(2)(mu-PPh(2))(mu-H)Pt(PPh(3))(MeCN)]PF6 were prepared by chloride abstraction from the corresponding neutral bimetallic species and show electrochemical behavior similar to the analogous Ru/Pt complexes.