HIGH-SPIN 4- AND 5-COORDINATE COBALT(2) AND NICKEL(2) COMPLEXES WITH A TRIDENTATE SNN SCHIFFBASE

The Schiff base formed by o-methylthiobenzaldehyde and N,N-diethylethylenediamine (MSBen-N(C2H5)2, set of donor atoms SNN) forms high-spin complexes with cobalt(II) and nickel(II) salts of the general formula M(MSBen-N(C2H5)2)X2. The stereochemistry of these complexes, both in the solid state and in solution, has been studied by magnetic and spectrophotometric measurements. The nickel halide complexes are five-coordinate in the solid state, whereas in solution in inert solvents they give rise to temperature-dependent equilibria between tetrahedral and five-coordinate species. The cobalt halide complexes are pseudo-tetrahedral both in the solid state and in solution. Nickel(II) iodide catalyzes demethylization of the sulfur atom of the ligand. © 1968, American Chemical Society. All rights reserved.