Copper(II) Complexes of Tridentate Schiff Bases of 5‐Substituted Salicylaldehydes and Diamines – The Role of the Substituent and the Diamine in the Formation of Mono‐, Di‐ and Trinuclear Species – Crystal Structures and Magnetic Properties

We describe some copper(II) complexes with tridentate anionic Schiff bases, L – , derived from the monocondensation of some 5‐substituted salicylaldehydes (5‐G‐salH, G = H, NO 2 and OMe) with ethylenediamine (en) or 1,3‐diaminopropane (tn). Mononuclear [CuL(py)] + , dinuclear [Cu 2 L 2 ] 2+ and trinuclear [Cu 3 L 3 (μ 3 ‐OH)] 2+ compounds have been obtained, and factors affecting the nuclearity of complexes were investigated and found to depend on reaction conditions, the nature of G and the length of the diamine. The crystal structures of seven representative compounds have been determined. Magnetic studies on a dinuclear and a trinuclear species were also carried out, and the results were interpreted on the basis of the structural data and current superexchange models. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)