Synthesis and coordination behaviour of a novel tridentate P,N,O-ketiminate ligand

Abstract

Treatment of o-(diphenylphosphino)aniline with 3-formylacetylacetone led to the formation of the ketimine type Schiff base 3-((o-diphenylphosphino-phenylamino)-methylene)-pentane-2,4-dione (o−PPh2−C6H4−NH−CH=C(COCH3)2, HL). Complexes [ML2] (M=Fe, Co, Ni, Cu) were obtained from the reaction of HL with the corresponding metal acetate or acetylacetonate derivatives. The [ML2] complexes (M=Fe, Co, Ni) exhibit a distorted octahedral coordination from two tridentate P,N,O ketiminate ligands L−. The arrangement of the ligands is meridional in the case of [FeL2] and [NiL2]. The cobalt complex [CoL2] displays a facial coordination. In the case of the nearly square planar copper complex [CuL2], only the ketiminate functionalities of the ligands are involved in coordination and the participation of the PPh2 groups is neglectable.