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, namely, N-2-hydroxybenzylsalicylaldimine (I), N-2-hydroxy-1-naphthylmethylsalicylaldimine (II), N-2-hydroxybenzyl-2-hydroxy-1-naphthaldimine (III) and N-2-hydroxy-1-naphthylmethyl-2-hydroxy-1-naphthaldimine (IV) have been studied. The ligands (III) and (IV) were found to form complexes of the composition NiL(2) (where L represents the Schiff base). The Ni(II) complexes of Schiff bases (I) and (II) were not obtained in crystalline form. In the presence of n-butylamine, however, all Schiff bases formed Ni(II) complexes of the composition NiL'(2), where L' represents 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). Since all the complexes are diamagnetic, the coordination of Ni(II) was considered to be square-planar.