Synthesis, structural determination and magnetic properties of three new di-μ 1,3-azido copper(II) dimers derived from tridentate amines: magneto-structural correlations

Abstract

Three new copper(II) dinuclear complexes, derived from the μ 1,3-azido bridging ligand and tridentate amines, were synthesised and their crystal structures determined by X-ray diffraction methods. [Cu 2(μ-N 3) 2(Me 5dien) 2](ClO 4) 2 ( 1), [Cu 2(μ-N 3) 2(Et 5dien) 2](ClO 4) 2 ( 2), and [Cu 2(μ-N 3) 2(EtMe 4dien) 2](ClO 4) 2 ( 3). Me 5dien is 1,1,4,7,7-pentamethyldiethylenetriamine, Et 5dien is 1,1,4,7,7-pentaethyldiethylenetriamine and EtMe 4dien is 4-ethyl-1,1,7,7-tetramethyldiethylenetriamine. The three new dinuclear compounds are asymmetrical double bridging μ 2-1,3 azido pentacoordinate copper(II) compounds. Variable temperature magnetic susceptibility data showed antiferromagnetic coupling for all of them. These data were fitted to the appropriate equation derived from the Hamiltonian H=− JS 1 S 2 giving the parameters J=−7.5(6) cm −1, g=2.048(14) for 1; J=−28(3) cm −1, g=2.09(8) for 2; and J=−3.6(4) cm −1, g=2.062(8) for 3.