Ligand effect on the growth reaction of copper(II) dicyanamide complexes: Syntheses, characterization and X-ray single crystal structure analyses of [CuL{N(CN)2}2]n and [CuL'{N(CN)2}2]2 [L=2-(aminoethyl)pyridine and L'=2-(aminomethyl)pyridine]

The ligands 2-(aminoethyl)pyridine (L) and 2-(aminomethyl)pyridine (L') have been chosen to study the role of the organic co-ligands on the geometry of Cu(II)-dicyanamide system. On complexation with L polymeric species is obtained, whereas, the growth reaction is observed to be terminated after dimerization on complexation with L'. The polymeric species, [CuL{N(CN)(2)}(2)](n), and the dimeric species, [CuL'(N(CN)(2)}(2)](2), have been characterized by routine physicochemical techniques and by single crystal X-ray diffraction and their formation has been rationalized. Two types of coordination modes of dicyanamide, monodentate and mu(1,5) are observed in both the complexes. (C) 2007 Elsevier B.V. All rights reserved.