Theoretical studies on organic transition metal complexes. Part 4. An investigation of electronic and structural effects in o-hydroxyaryloximes

Abstract

The observed differences in selectivity between salicylaldoximes and 2-hydroxyacetophenone and 2-hydroxybenzophenone oximes as reagents for the extraction of copper from aqueous acids has been examined in terms of electronic and structural differences within the ligands. Geometry optimisation studies are reported on salicylaldoxime at the CNDO/2, MINDO/3, MNDO, AMI, STO-3G, STO-6G and 3-21G levels and the results compared with the known crystallographic data. Geometries for the other oximes with unknown structures have been generated using the STO-3G method. The results obtained from the calculations suggest that steric factors are responsible for the different extraction behaviour.