Synthesis, structural determination and magnetic properties of three new di-μ1,3-azido copper(II) dimers derived from tridentate amines:: magneto-structural correlations

Three new copper(II) dinuclear complexes, derived from the mu(1.3)-azido bridging ligand and tridentate amines, were synthesised and their crystal structures determined by X-ray diffraction methods. [Cu-2(mu-N-3)(2)(Me(5)dien)(2)](ClO4)(2) (1), [Cu-2(mu-N-3)(2)(Et(5)dien)(2)]-(ClO4)(2) (2), and [Cu-2(mu-N-3)(2)(EtMe(4)dien)(2)](ClO4)(2) (3). Me(5)dien is 1,1,4,7,7-pentamethyldiethylenetriamine, Et(5)dien is 1,1,4,7,7-pen taethyldiethylenetriamine and EtMe(4)dien is 4-ethyl-1,1,7,7-tetramethyldiethylenetriamine. The three new dinuclear compounds are asymmetrical double bridging mu(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. (C) 2000 Elsevier Science S.A. All rights reserved.