Synthesis and magnetic properties of dithiooxamide-bridged nickel(II) complexes

Two novel nickel(II) dinuclear complexes [Ni-2(cyclam)(2)(DTA)](ClO4)(2) (1 ) and [Ni-2(TAA)(2)(DTA)] (ClO4)(2) (2) (TAA = N(CH2CH2NH2)(3), cyclam = 1, 4,8,11-tetraazacyclotetradecane, DTA = dithiooxamide) have been prepared an d studied by elemental analyses, i.r. and electronic spectra and magnetic m easurements. The magnetic susceptibility temperature dependence was measure d over the 77-300 K range and the observed data were successfully simulated by an equation based on the spin Hamiltonian operator (H = -2JS(1)S(2)) gi ving the exchange integral J = -23.09 cm(-1) for (1) and J = -26.0 cm(-1) f or (2).