Coordination chemistry of copper(II) with oxaaza macrocyclic ligands.: Crystal structure of a dinuclear tetramer copper(II) complex

A new series of copper(11) nitrate and perchlorate complexes with eight 6 different oxaaza macrocyclic ligands (L-1-L-8) have been prepared and characterised. Complexes with the diiminic ligands L-1-L-6 have been obtained by template condensation of the appropriate dialdehyde and diamine precursors; the reduced L-7 and L-8 macrocycles have been synthesised using a direct route. The overall geometry and bonding mode have been deduced on the basis of elemental analysis data, IR, FAB, UV-Vis spectroscopy, cyclic voltammetry, and conductivity and magnetic susceptibility measurements. After treatment of an acetonitrile solution of the complex [(LCu)-Cu-6](ClO4)(2).5H(2)O with acetic acid 15%, dark blue single crystals, the result of a secondary reaction, were isolated and characterised as a new binuclear tetramer copper(11) complex, with formula C13H28ClCu2N3O10. (C) 2003 Elsevier Science Ltd. All rights reserved.