Sulphur-nitrogen chelating agents. VII. Five- and six-coordinate complexes of cobalt(II), nickel(II), and copper(II) with an S-N-S tridentate ligand

Abstract

Mono-ligand complexes of the tridentate ligand N-(2-methylthiophenyl)- 2?-methylthiophenylmethyleneimine (SNS) of the type MX₂(SNS) (M = Co, Ni, Cu; X = Cl, Br, I, or FCS) have been prepared. The electronic spectra indicate that the cobalt halide complexes are five-coordinate, whereas the complex Co(NCS)₂- (SNS) and the nickel complexes are six- coordinate and polymeric. The copper complexes CuX₂(SNS) (X = Cl, Br) are possibly five-coordinate.     The bis-complexes of nickel [Ni(SNS)₂]X₂ (X = ClO₄, BF₄) are high- spin but the complex [Co(SNS)₂](ClO₄)₂ appears to be a rare example of a low-spin octahedral complex of cobalt(II).