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

The Schiff base, 2-chlorophenylsalicylaldimine (HL1), 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)(PPh3)2] (R = H, CHdouble bond; length as m-dashCHC6H5, CHdouble bond; length as m-dashCHC6H4Me-4, CHdouble bond; length as m-dashCHtBu, CCtriple bond; length of mdashCPhdouble bond; length as m-dashCHPh; BTD = 2,1,3-benzothiadiazole) to form the compounds [RuR(L1)(CO)(PPh3)2] through displacement of the chloride and BTD ligands. An analogous reaction occurs with the osmium complex [OsHCl(CO)(BTD)(PPh3)2] to provide [OsH(L1)(CO)(PPh3)2]. The compound [Ru(CHdouble bond; length as m-dashCHC6H4Me-4)(L2)(CO)(PPh3)2] is formed through reaction of salicylaldehyde (HL2) with [Ru(CHdouble bond; length as m-dashCHC6H4Me-4)Cl(CO)(BTD)(PPh3)2] in the presence of base. Two further ligands were investigated to extend the study to encompass 5- and 4-membered chelates; 8-hydroxyquinoline (HL3) and 2-hydroxy-4-methylquinoline (HL4) react with [Ru(CHdouble bond; length as m-dashCHPh)Cl(CO)(BTD)(PPh3)2] and [Ru(CHdouble bond; length as m-dashCHC6H4Me-4)Cl(CO)(BTD)(PPh3)2] in the presence of base to yield the complexes [Ru(CHdouble bond; length as m-dashCHPh)(L3)(CO)(PPh3)2] and [Ru(CHdouble bond; length as m-dashCHC6H4Me-4)(L4)(CO)(PPh3)2], respectively. The crystal structure of [Ru(CHdouble bond; length as m-dashCHC6H4Me-4)(L1)(CO)(PPh3)2] is reported.