Effect of the counter-anion on the structural and magnetic properties of a copper(II) complex with 2-[(bis(2-pyridylmethyl)amino)methyl]-4-methyl-6-(methylthio)phenol

Abstract

A new 2-[(bis(2-pyridylmethyl)amino)methyl]-4-methyl-6-(methylthio)phenol copper(II) perchlorate, complex, [Cu-2(mu-SL)(2)](ClO4)(2) (1), was synthesized and magnetically and structurally characterized. The complex consists of two similar but not equivalent [Cu-2(mu-SL)(2)](2+) bimetallic cations designed as P and Q. Cation P has a square-base pyramidal cupric centre bonded to an approximately trigonal bipyramidal one, while cation Q has two equivalent square-base pyramidal copper centres, related by an inversion center. The cupric centres in both units are bridged by two phenolate oxygen atoms from two deprotonated HSL molecules, defining a central Cu2O2 core. Each Cu-II centre has a N3O2 coordination sphere. Magnetic studies done for (1) show an overall weak antiferromagnetic behavior. The best fit of the experimental data was obtained using a modified Bleaney-Bowers equation with g(1) = g(2) = 2.05, J(P) = -13.4 cm(-1) and J(Q) = +5.22 cm(-1) for P and Q, respectively. The properties of the new complex are compared to those reported for the hexafluorophosphate complex with the same ligand, in terms of the effect of the distortion caused by the use of a different anion. (C) 2013 Elsevier Ltd. All rights reserved.