Mixed ligand tris-chelate of copper(II) with N,N-donor ligands - Synthesis, structure and spectra of [Cu(en)(phen) < inf > 2 < /inf > ]X < inf > 2 < /inf > ·2phen·8H < inf > 2 < /inf > O (X = Cl < sup > - < /sup > , NO < inf > 3 < /inf > < sup > - < /sup > )

Abstract

[Cu(en)(phen)2]+ is crystallized along with two phenanthroline and eight lattice water molecules either as a chloride or a nitrate salt. The cation has almost identical structural and spectral properties which correspond to a tetragonally elongated octahedral geometry with the en ligand in the equatorial plane. EPR parameters reveal a slight rhombicity in the coordination polyhedron. Even though both compounds have the same composition (except for the anions), the hydrogen bond networks involving the lattice water molecules and anions are quite different in the two compounds. There are also extensive π-stacking interactions involving the phenanthroline molecules, both coordinated and non-coordinated. The non-bonding interactions have a major directing role in the crystallization of the tris-chelate cation. The analogous mixed ligand complex of 2,2-bipyridine could not be crystallized. © 2010 Elsevier Ltd. All rights reserved.