Coordination modes of 1-allyl benzotriazole: synthesis and characterization of cobalt(II), nickel(II), copper(II), copper(I) and silver(I) complexes

Abstract

The synthesis and coordination behaviour of 1-allylbenzotriazole (ABT), containing both σ-donating heterocyclic ring nitrogen(s) and a π-bonding olefinic group, has been studied by complexation with CoII, NiII, CuII, CuI and AgI salts. The solid complexes M(ABT)2X2 (M=Co, Ni or Cu and X=a counterion) and M(ABT)X (M=Cu or Ag and X=Br, I, or NO3) have been characterised by1H-n.m.r. (representative CuI species) and other physical data. Different modes coordination for the title ligand have been proposed based upon i.r. data which indicate the participation of a σ-donating ring nitrogen only in complexes with bivalent metal salts, and the involvement of both the ring nitrogen and the allylic olefinic component in bonding to a monovalent metal ion.1H-n.m.r. data are qualitatively commensurate with participation of the allyl group in monovalent metal complexes.