Magnetic properties of nickel(III) bis(benzene-1,2-dithiolate); (n-Bu4N)[Ni(dmbit)2] and (n-Bu4N)[Ni(dmbbip)2]

The nickel complexes with benzene-1,2-dithiolate, (n-Bu4N)[NiL2] (1 ; L = 5,6-dithiobenzo[d] -1,3-dithiole-2-thione or dmbit : 2 ; L = 1,2-di(isopropylthio)benzene-4,5-dithiole or dmbbip), have been synthesized by iodine oxidation of dianionic complexes. Two-probe r.t. conductivities of 1 and 2 are 6×10−9 and 7×10−11 S/cm, respectively. The effective magnetic moments of 1 and 2 were measured as 1.74 and 1.75B.M., respectively, which implies the low-spin d7 state of Ni(III) (S = 12) with the electronic configuration of (dxz2dyz2(dxydz2) 3dz2-y20). The anisotropic epr g-values of 1 (g// = 2.158 and g⊥ = 2.030) and 2 (gxx = 2.147, gyy = 2.072 and gzz = 2.015) also support the fact that the paramagnetic nickel(III) ion is stabilized in the axial/rhombic symmetry. The corrected susceptibilities were fitted with the 2D-Heisenberg antiferromagnet model of S = 12 system. The spin-exchange parameters, …J…/k, have been estimated as 11.4K and 0.45K for 1 and 2, respectively.