The stability constants of adducts of nickel (II)diphenylthiocarbazonate(NiDz2 ) with different nitrogen bases was determined by using Job’s continuous variation method spectrophotometrically in chloroform solution. In case of bidentate bases the Job’s curves displayed a maximum at a mole fraction XNiDz2 = 0.5 indicating the formation of adducts with 1:1 NiDz2 to bidentate bases and mole fraction XNiDz2 = 0.66 indicating the formation of adducts with 1:2 NiDz2 to monodentate bases. The planar complex nickel (II)diphenylthiocarbazonate; diamagnetic, with dsp2 hybridization, which forms adducts with two molecules of various monodentate nitrogen bases and one molecule with bidentate nitrogen bases. The main factor controlling the stability of the adducts have been investigated and relationship between the base strength and coordination tendency towards nickel (II)diphenylthiocarbazonate is discussed in terms of steric factors.
