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 μ1,5 are observed in both the complexes.