NICKEL(II) COMPLEXES OF SUBSTITUTED DIPHENYLCARBAZONES AND THEIR ADDUCTS WITH HETEROCYCLIC NITROGEN BASES

The complexing behaviour of novel 1,5-di(4-chloro-2-methylphenyl)carba zone and 1,5-di(2,4-dichlorophenyl)carbazone towards nickel(II) ions h as been investigated by elemental analysis, magnetic susceptibility, u .v. -vis., i.r. and H-1-n.m.r. spectral studies. The ligands act as bi dentate N,O donors and form 1:2 complexes with the metal ions. The add ucting behaviour of nickel(II) complexes with nitrogen bases has been studied spectrophotometrically in a chloroform monophase. The nickel(I I) di(4-chloro-2-methylphenyl)carbazonate forms hexacoordinate adducts with monodentate and bidentate bases with 1:2 and 1:1 chelate:base st oichiometries, respectively, whilst, nickel(II) di(2,4-dichlorophenyl) carbazonate forms penta- and hexacoordinate adducts of 1:1 chelate:bas e stoichiometry with monodentate and bidentate bases, respectively. Th e results are discussed on the basis of steric properties and the basi city of the nitrogen bases.