A Chemical and Magnetic Study of Some Bivalent Nickel Complexes

Diamagnetic and square-coordinated nickel(I1) complexes of nitrogen substituted salicylaldimines, [Ni(N-R salicylaldimine),] (R=CH,, C,H,, and C,H,), readily react with l,l0-phenanthroline (phen) in benzene and form paramagnetic (p-3.2 B.M.) six-covalent complexes of the type [Si(phen)(N-R salicylaldimine),]. Similar para- magnetic monophenanthroline adducts are formed by the diamagnetic [X(o-hgdroxy- acetophenoxime),] and [Xi(N-methyl-o-hydroxyacetophenimine),] complexes. he paramagnetic (p-3.2 B.X.) nickel-salicylaldehyde complex, [Ni(~alicylaldeh~de),(H~O)~], reacts with h o l e s of the ligand forming the paramagnetic (p-3.2B.M.) derivative, Ki(phen)2(salicylaldehyde),.3H,0. This is an electrolyte in nitrobenzene and possesses the structure Diagram The cornplex cation was isolated as its perchlorate, Diagram 1 l h e dlamagnetlc aldimine derlvatlre [~l(salicylaldimine),1 also reacts with 2 moles of 1,lO-phenanthrohne, with partlal h~drolysis of the lmme, and fornls the unusual compound : Sl(phen),(sal1cylald1~ni~1e)(sal~cylaldehyde).3H~O. This paramagnetic com- pound is also an electrolyte in mtrobenzene and possesses the structure Diagram The follommg diamagnetic compounds, [Si(o-hydroxyacetophennnme),], [Nl(o- hpdroxyacetophenoxm~e)~], and [Ni(S-methj 1-o-hydroxj acetophenimine),], are con- verted by heat to paranlagnetlc forms whlch exhlblt an unusual temperature variation of the~r magnetlc moments. They revert to thelr orlginal diamagnetic forms on recrystallizat~on from chloroform.