Chemistry of mixed ligand complexes—II: The effect of coordination of mixed ligands on the bond relations of transition metal dioxime chelates

Abstract

Cobalt(II)-dimethylglyoxime was proved by spectrophotometric equilibrium measurements to coordinate chloride, bromide, iodide, thiocyanate and selenocyanate ions and iron(II)-dimethylglyoxime thiocyanate and selenocyanate ions. The mixed complexes formed are of low spin. The composition and stability constants of the mixed complexes were determined. The stability constants showed that halide or pseudohalide ions are bound stronger by dimethylglyoxime complexes than by the corresponding aquocomplexes. I.R. spectrometric measurements showed that thiocyanate and selenocyanate ions are bound in the mixed complexes by the sulfur and selenium, respectively. The effect of alkali metal cations on the stability of the mixed complexes was also investigated.