Trigonal pyramidal (CuN4)-N-I cores assembled by a family of tetradentate N-donor Schiff bases. Substituent effects on the Cu(II/I) potential

Tocher, D.A., Drew, M.G.B., Chowdhury, S. and Datta, D. (2003) Trigonal pyramidal (CuN4)-N-I cores assembled by a family of tetradentate N-donor Schiff bases. Substituent effects on the Cu(II/I) potential. Indian Journal of Chemistry Section A, 42 (5). pp. 983-989. ISSN 0376-4710

Abstract/Summary

Copper(l) complexes of 1:3 condensates of tris(2-aminoethyl)amine and p-X-benzaldehydes (X = K Cl, NMe2 and NO2) of the type [Cu(ligand)]ClO4 are synthesised. The X-ray crystal structures of the copper(l) complexes with X = K, Cl and NMe2 are determined. In these complexes copper(l) is found to have trigonal pyramidal N-4 coordination sphere with the apical N forming a longer bond (2.191-2.202 Angstrom) than the trigonal ones (2.003-2.026 Angstrom). The Cu(II/I) potentials in these complexes span a range of 0.71-0.90 V vs SCE increasing linearly with the resonance component of the Hammett sigma for the para substituent X. It is concluded that trigonal pyramidal geometry is destabilising for copper(II).