MAGNETIC-PROPERTIES OF NICKEL(III) BIS(BENZENE-1,2-DITHIOLATE)(N-BU(4)N)[NI(DMBIT)(2)] AND (N-BU(4)N)[NI(DMBBIP)(2)]

The nickel complexes with benzene-1,2-dithiolate, (n-Bu(4)N)[NiL(2)] ((1) under bar ; L = 5,6-dithiobenzo[d]-1,3-dithiole-2-thione or dmbit : (2) under bar ; L = 1,2-di(isopropylthio)benzene-4,5-dithiol or dmbbip), have been synthesized by iodine oxidation of dianionic complexes. Two-probe r.t. conductivities of (1) under bar and (2) under bar are 6x10(-9) and 7x10(-11) S/cm, respectively. The effective magnetic moments of (1) under bar and (2) under bar were measured as 1.74 and 1.75B.M., respectively, which implies the low-spin d(7) State of Ni(III) (S = 1/2) with the electronic configuration of (d(xz)(2)d(yz)(2)(d(xy)d(z2))(3)d(z2)(0)). The anisotropic epr g-values of (1) under bar (g(//)= 2.158 and g(perpendicular to) = 2.030) and (2) under bar (g(xx) = 2.147, g(yy) = 2.072 and g(zz) = 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 = 1/2 system. The spin-exchange parameters, \J\/k, have been estimated as 11.4K and 0.45K for (1) under bar and (2) under bar respectively.