Influence of functionalities over polymer, trimer, dimer formation and optical properties of cadmium dithiocarbamates

Abstract

Homoleptic cadmium(II) bis(dithiocarbamate) complexes having polymeric [Cd(L)2]∞(L = C7H5O2CH2NCS2CH2C6H5(L1), 1; C6H4NO2CH2NCS2CH2C4H3O (L2), 2; C6H4FCH2NCS2CH2C4H3O (L3), 3), trinuclear [Cd(L4)2]3(L4 = 4-ClC6H4CH2NCS2CH2C4H3O, 4) and dinuclear [Cd(L5)2]2, (L5 = 3-ClC6H4CH2NCS2CH2C6H5, 5) structures have been synthesized and characterized by elemental analyses, spectroscopy (IR,1H and13C {1H} NMR and UV–Vis.) and their structures have been revealed by X-ray crystallography. In 1–3 the dithiocarbamate ligands are uniquely bonded to the Cd atoms in a μ2,κ2S,S-chelating-bridging fashion, portraying 1D coordination polymeric structures in which the cadmium(II) ions adopt six coordinate distorted octahedral structures. In 4 the six dithiocarbamate ligands are spectacularly arranged about the Cd atoms resulting in a centrosymmetric trinuclear complex in which the central metal adopts an octahedral geometry and the terminal Cd atoms are in square pyramidal environments. Complex 5 has the well-established centrosymmetric dimeric structure in which the metal atoms have a five-coordinate trigonal bipyramidal geometry. Complexes 1–4 are rare examples of polymeric and trinuclear cadmium dithiocarbamate complexes. 1–5 show luminescent characteristics in solution and in the solid state arising from the metal perturbed intra-ligand charge transfer (ILCT) states. Their TG analyses show a single step decomposition with the formation of CdS nanoparticles, which have been examined by PXRD and HRTEM. © 2016 Elsevier Ltd