SOME COMPLEXES OF NICKEL(II) WITH ONO TYPE SCHIFF-BASES AND THEIR MONOLIGAND ADDUCTS .2.

Coordination compounds of Ni(II) with four ONO-type Schiff bases, name ly, N-2-hydroxybenzylsalicylaldimine (I), N-2-hydroxy-1-naphthylmethyl salicylaldimine (II), N-2-hydroxybenzyl-2-hydroxy-1-naphthaldimine (II I) and ydroxy-1-naphthylmethyl-2-hydroxy-1-naphthaldimine (IV) have be en studied. The ligands (III) and (IV) were found to form complexes of the composition NiL(2) (where L represents the Schiff base). The Ni(I I) complexes of Schiff bases (I) and (II) were not obtained in crystal line form. In the presence of n-butylamine, however, all Schiff bases formed Ni(II) complexes of the composition NiL'(2), where L' represent s Schiff bases formed by an amine exchange between L and n-butylamine. Furthermore, in the presence of piperidine, (I), (II), (III) and (IV) gave complexes of the composition NiLL '', (L '' is piperidine). Sinc e all the complexes are diamagnetic, the coordination of Ni(II) was co nsidered to be square-planar.