# Cadmium–halide and mixed cadmium–halide–dicyanamide polymers mediated by ancillary 2-aminoalkyl-pyridine ligands: Synthesis, X-ray single crystal structures and luminescence property

Chattopadhyay, Tanmay and Banerjee, Arpita and Banu, Kazi Sabnam and Suresh, Eringathodi and Netahji, Munirathinam and Birarda, Giovanni and Zangrando, Ennio and Das, Debasis (2008) Cadmium–halide and mixed cadmium–halide–dicyanamide polymers mediated by ancillary 2-aminoalkyl-pyridine ligands: Synthesis, X-ray single crystal structures and luminescence property. In: Polyhedron, 27 (11). pp. 2452-2458.

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## Abstract

A series of mixed halide–dicyanamide and halide complexes of cadmium(II) mediated by 2-aminoalkylpyridine ligands [2-aminomethylpyridine (ampy) and 2-aminoethylpyridine (aepy)] have been synthesized. Five of them, $[CdCl(dca)(aepy)]_n$ (1), $[CdBr(dca)(ampy)]_n$ (2), $[CdCl(dca)(ampy)]_n$ (3)(dca = dicyanamide); $[CdI_2(aepy)]_n$ (4), and $[CdI_2(ampy)]_n$ (5), (dca = dicyanamide) have been characterized by X-ray single crystal structure analysis. The structural determination shows that the compounds are 1D coordination polymers, with the exception of 3 that gives origin to a 2D sheet-like network. The ampy and aepy ligands (also with the occurrence of dca anions in 1–3) reveal to be useful ancillary fragments for the construction of unprecedented Cd–halide polymeric species. The crystal packing shows that the dimensionality of all compounds is enlarged to 2D, and 3D in the case of complex 3, through \pi – \pi interactions occurring between the pyridine rings. All the species exhibit interesting luminescence property in solution as well in solid state which is originated from ligand-centered \pi – \pi* transitions.The fluorescence band maxima and fluorescence efficiency (in methanol) are found to be dependent not only on the pyridine ligand but also on the type of halide, and the co-ligand. Solid state luminescent study implies that p–p interactions occurring between pyridine rings are also important in controlling the fluorescence intensity. Amongst the synthesized complexes reported, complex 5 exhibits the highest fluorescence efficiency in methanol.

Item Type: Journal Article Publisher Copyright of this article belongs to Elsevier. Mixed halide–dicyanamide polymers;Crystal structures; Luminescence property. Division of Chemical Sciences > Inorganic & Physical Chemistry 08 Sep 2008 06:59 04 Jan 2013 07:21 http://eprints.iisc.ernet.in/id/eprint/15710