Molecular orbital calculations on transition-metal complexes. Part IV. Square planar copper(II) complexes

Abstract

CNDO MO Calculations are reported for the square planar Cu^II complexes CuL₂(L = dimethylglyoximato, acetylacetonato, and salicylideneiminato), Cu(porphin), Cu(H₂O)₆²⁺, Cu(C₂O₄)₂^2–, Cu(CN)₄^2–, and for the distorted octahedral complexes of bis(acetylacetonato)- and bis(dimethylglyoximato)-copper produced by axial co-ordination of water and also ammonia. The covalency in the resulting d eigenfunctions correlates extremely well with the values derived from electron paramagnetic resonance measurements. The calculations yield transferred spin densities to the ligands which are generally a factor of ca. 2 smaller than those obtained from superhyperfine couplings in the e.s.r. spectrum.