Cyclometallated complexes of ruthenium and osmium containing the o-C6H4PPh2 ligand

The reaction between [Hg(o-C6H4PPh2)(2)] and [MHCl(CO)(PPh3)(3)] gives the complexes [MCl(o-C6H4PPh2)(CO)(PPh3)(2)] [M = Ru (1), Os (2)], which contain a four-membered cyclometallated ring. A single-crystal X-ray diffraction study of 2 shows the geometry about osmium to be distorted octahedral with the phosphorus atoms in a meridional arrangement. Both complexes react with CO, which displaces one of the triphenylphosphine ligands, the product from 2 being [OsCl(o-C6H4PPh2(CO)(2)(PPh3)]. In the case of 1, there is an accompanying migratory insertion of coordinated CS) into the Ru-C bond to give the five-membered cyclic acyl complex [RuCl(o-C(O)C6H4PPh2)(CO)(2)(PPh3)] . Complex 2 reacts with AgSbF6 in the presence of CO to give [Os(o-C6H4PPh2)(CO)(2)(PPh3)(2)]SbF6. (C) 2000 Elsevier Science S.A. All rights reserved.