Guanididium and alkylammonium ion complexation by nickel(II) Schiff base complexes

Abstract

Guanidinium tetraphyenylborate, [C(NH₂)₃]BPh₄, reacted with N,N′-ethylenebis(salicylideneaminato)nickel(II), [Ni(salen)], in thf to from {[Ni(salen)]₃[C(NH₂)₃]}(BPh₄).2thf, whose X-ray analysis showed that the guanidinium ion is encapsulated in a provided by the six oxygens of the three [Ni(salen)] units and held in place by six strong hydrogen bonds; the same complexation occurred using alkylammouim tetraphenylborate derivatives, which enhance significantly the solubility of nickel(II) Schiff base complexes in organic solvents.