DENSITY FUNCTIONAL CALCULATIONS OF DIOXYGEN BINDING IN MONO- AND DINUCLEAR COPPER COMPLEXES

摘要

We studied the electronic structure, electronic excitation energies, charge distribution, and magnetic properties of three dinuclear copper complexes, [{[L-Cu](2)O-2}(2+), L = 1,4,7-triaza-cyclo nonone] (1), [{[L-Cu](2)O-2}(2+), L = hydrotis-(pyrazolyl)-borate (2) and {[(NH3)(3)-Cu](2)O-2}(2+) (3) in two core isomers. The theoretical model complex 3 is sufficient to describe the qualitative electronic structure and related properties of 1 and 2. The main features of the electronic structure are similar between the three systems; the electronic excitation energies between copper-and oxygen-based orbitals are insensitive to ligand effects. In addition, we studied the energetics of mononuclear complexes to determine the mechanism of the formation of 1. In the suggested mechanism the end-on mononuclear complex forms first followed by an isomerization between the trans-mu-1,2-O-2, mu-eta(2):nu(2)-O-2 and (mu-O)(2) dinculear isomers. (C) 1997 John Wiley & Sons, Inc. [References: 64]