Mononuclear Ru(II) Carbonyl Complexes Containing Quadridentate Schiff Bases as N2O2 Donors: Synthesis, Spectral, Catalytic Properties, and Antibacterial Activity

Abstract

Reactions of Ru3(CO)12with novel tetradentate Schiff bases ligands H2L1−5 in benzene under reduced pressure afforded the formation of new Ru(II) complexes of the type [Ru(CO)2(L1−5)] where L = anion of N,N/bis(salicylaldehyde)4,5-dimethyl-1, 2-phenylenediamine (saldmophn), N,N/bis(salicylaldehyde)4,5-dichloro-1,2-phenylenediamine (saldcophn), N,N/bis(salicylalde-hyde)2,3-diaminonaphthalene (saldnap), N,N/bis(o-vanillin)4, 5-dimethy-l,2-phenylenediamine (ovaldmophn), and N,N/bis(o-vanillin)4,5-dichloro-1,2-phenylenediamine (ovaldcophn), respectively. All the newly synthesized complexes were investigated using elemental analysis, FT-IR, UV-Vis, mass spectrometry, and magnetic measurements. An octahedral structure has been tentatively proposed for the new complexes. All the new complexes have been found to be efficient catalysts for oxidation of primary and secondary alcohols into corresponding carbonyl compounds in presence of N-methylmorpholine-N-oxide (NMO) as the source of oxygen. In view of the biological activity, the ligands showed moderate bactericidal activities, where upon chelation with ruthenium, the bactericidal activities increased and the results have been compared with some known antibiotics.