Transfert réciproque d'oxygéne et d'hydrogéne entre deux ligands coordonnés à une ossature dinucléaire de ruthénium: synthèse et structure moléculaire de Ru2(CO)6(?-PCy 2)[?-P(O)Cy2]

The dinuclear propionato complexes (RU2(CO)4(?-O2CEt)2(PR2H)2 (R = Ph: 1,R = Cy: 2) react under carbon monoxide pressure to give the phosphido complexes Ru2(CO)6(?-PR2)2 (R = Ph: 3, R = Cy: 4) as well as the phosphido-phosphinito complexes Ru2(CO6(?-PR2)[?-P(O)R2] (R = Ph: 5, R = Cy: 6). The simultaneous formation of propionic acid and propionic aldehyde suggests that a H-atom is transferred from the phosphine to the propionato ligand, while an O-atom is transferred from the propionato to the phosphine ligand. The single-crystal X-ray structure analysis of 6 reveals this dinuc1ear complex to have a 'sawhorse' type structure in which the RU2 backbone is bridged by a ?2-phosphido and a ?2-phosphinito ligand.