Complexes of ruthenium with tridentate [P,N,O] ligands

Tridentate ligands with [P,N,O] donor sets, prepared either by the condensation of 2-(diphenylphosphino)benzaldehyde with 1S,2R-norephedrine (HL1) or 2-aminophenol (HL2) or by the condensation of 2-(diphenylphosphino)aniline with salicylaldehyde (sal) (HL3), 5-(NO2)sal (HL4), 5-(Cl)sal (HL5), 5-(Br)sal (HL6), 5-(MeO)sal (HL7) or 3-(MeO)sal (HL8), reacted with [(RuCl2)-Cl-II(dmso)(4)] in refluxing thf solution to yield complexes of the general formula cis-[(RuCl)-Cl-II(eta(3)-L1-8)(dmso)(2)]. Use of two equivalents of ligand HL1 resulted in the formation of mer-[Ru-II(eta(3)-L-1)(2)], a reaction not seen for HL2-8. Aerial oxidation of cis,mer-[(RuCl)-Cl-II(eta(3)-L-3)(dmso)(2)] in a chloroform solution yielded cis,fac-[(RuCl2)-Cl-III(eta(3)-L-3)(dmso)], which has undergone an unexpected rearrangement of co-ordination geometry.