COMPLEXES OF THE PLATINUM METALS .17. MOLECULAR-DYNAMICS OF THE SPECIES [M(O2CR)2(CO)(PPH3)2] (M=RU,R=ME,CF3,C2F5,C6F5-M=OS,R=ME,CF3)

Intramolecular monodentate-bidentate carboxylate ligand exchange in the complexes [M(O2CR)2(CO)(PPh3)2] (M = Ru, R = Me, CF3, C2F5, C6F5; M = Os, R = Me, CF3) has been studied by variable-temperature 31P and 1H or 19F NMR. Kinetic data establish the participation of two mechanisms—a fast process involving cleavage of Ru-O bonds trans to phosphorus and a slower one involving rupture of the Ru-0 bond trans to carbonyl. In the presence of methanol or similar oxygen donors (L) species of the form [Ru(O2CR)2(CO)L(PPh3)2] and/or [Ru(O2CR)(CO)L(PPh3)2][O2CR] also participate in the rate processes. Values for thermodynamic parameters of activation are recorded. © 1979, American Chemical Society. All rights reserved.