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, NO2 and OMe) with ethylenediamine (en) or 1,3-diaminopropane (tn). Mononuclear [CuL(py)]+, dinuclear [Cu2L2]2+ and trinuclear [Cu3L3(μ3-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.