Ruthenium hydride and vinyl complexes supported by nitrogen–oxygen mixed-donor ligands

Abstract

The Schiff base, 2-chlorophenylsalicylaldimine (HL 1), is formed readily from salicylaldehyde and 2-chloroaniline. After deprotonation, this ligand is found to react as a bidentate mixed-donor chelate with the complexes [RuRCl(CO)(BTD)(PPh 3) 2] (R = H, CH CHC 6H 5, CH CHC 6H 4Me-4, CH CH t Bu, CC CPh CHPh; BTD = 2,1,3-benzothiadiazole) to form the compounds [RuR(L 1)(CO)(PPh 3) 2] through displacement of the chloride and BTD ligands. An analogous reaction occurs with the osmium complex [OsHCl(CO)(BTD)(PPh 3) 2] to provide [OsH(L 1)(CO)(PPh 3) 2]. The compound [Ru(CH CHC 6H 4Me-4)(L 2)(CO)(PPh 3) 2] is formed through reaction of salicylaldehyde (HL 2) with [Ru(CH CHC 6H 4Me-4)Cl(CO)(BTD)(PPh 3) 2] in the presence of base. Two further ligands were investigated to extend the study to encompass 5- and 4-membered chelates; 8-hydroxyquinoline (HL 3) and 2-hydroxy-4-methylquinoline (HL 4) react with [Ru(CH CHPh)Cl(CO)(BTD)(PPh 3) 2] and [Ru(CH CHC 6H 4Me-4)Cl(CO)(BTD)(PPh 3) 2] in the presence of base to yield the complexes [Ru(CH CHPh)(L 3)(CO)(PPh 3) 2] and [Ru(CH CHC 6H 4Me-4)(L 4)(CO)(PPh 3) 2], respectively. The crystal structure of [Ru(CH CHC 6H 4Me-4)(L 1)(CO)(PPh 3) 2] is reported.