An unprecedented CuII-Schiff base complex existing as two different trinuclear units with strong antiferromagnetic couplings

A new tetradentate N2O2 donor Schiff base ligand [OHC6H4CH=NCH2CH2CH(CH2CH3)N=CHC6H4OH = H2L] was obtained by 1:2 condensation of 1,3-diaminopentane with salicylaldehyde and has been used to synthesise an unusual copper(II) complex whose asymmetric unit presents two structurally different almost linear trinuclear units [Cu-3(mu-L)(2)(ClO4)(2)] [Cu-3(mu-L)(2)(H2O)(ClO4)(2)] (1). The ligand and the complex were characterised by elemental analysis, FT-IR, H-1 NMR and UV-Vis spectroscopy in addition electrochemical and single crystal X-ray diffraction studies were performed for the complex. The magnetic properties of 1 reveal the presence of strong intra-trimer (J(1) = -202(3) cm(-1) and J(2) = -233(3) cm(-1)) as well as very weak inter-trimer (zJ' = -0.11(1) cm(-1)) antiferromagnetic interactions. (c) 2009 Elsevier Ltd. All rights reserved.