UNIQUE COMPLEXATION BY THE TRIDENTATE LIGANDS, 6-DIPHENYLPHOSPHINO-2-PYRIDONATE (PYPHOS) AND 6-DIPHENYLPHOSPHINO-2-PYRIDONE (PYPHOSH), ON RUTHENIUM(II) - CRYSTAL-STRUCTURES OF (PYPHOSH)RUCL(MU-CL)MO2CL(PYPHOS)(3), RUCL2(CO)(PYPHOSH)(2), [RU(PYPHOS)(3)](MU-NA)(2)[RU(PYPHOS)(3)]

The diphenylphosphino-2-pyridone ligand (pyphosH) and its anion ligand , pyridonate (pyphos), coordinated to the ruthenium(II) center through two modes: bidentate P-N chelation and monodentate P coordination. Re action of Mo-2(pyphos)(4) (2) with [RuCl2(eta(6)-p-cymene)](2) (3) aff orded an unexpected trinuclear complex (pyphosH)RuCl(mu-Cl) Mo2Cl(pyph os)(3) (5) accompanied by a monomeric complex (eta(6)-p-cymene) RuCl2( pyphosH) (4). In complex 5, three pyphos ligands coordinated to a qua druply-bonded Mo-2 core in three different modes: O-N chelation with f ree phosphine moiety, O-N chelation with a phosphorus atom bound to a ruthenium atom, P-N chelation with an oxygen atom bridged to the ruthe nium atom; thereby the pseudo octahedral ruthenium center was surround ed by a phosphorus atom and a nitrogen atom of a pyphosH: ligand (P-N chelation), two trans-arranged chloro atoms, the oxygen atom and the p hosphorus atom of the two pyphos ligands. Reaction of RuClx(CO)(y) wit h pyphosH gave a mononuclear complex RuCl2(CO) (pyphosH)(2) (6), which has two pyphosH ligands bound to the ruthenium atom through P-N chela tion and monodentate P coordination and involves two hydrogen bondings , NH ... Cl and OH ... Cl. In addition, treatment of Ru-2(OAc)(4) (7) with the sodium salt of the pyphos ligand afforded a heterotetrametall ic complex [Ru(pyphos)(3)](mu-Na)(2)[Ru(pyphos)(3)] (8) in which each pseudo octahedral ruthenium(II) center has three pyphos ligands throug h P-N chelation and two sodium ions were coordinated by four oxygen at oms in distorted tetrahedral geometry. (C) 1998 Elsevier Science S.A.