Synthesis, structure, spectroscopic properties, and theoretical studies of a new blue/green luminescent complex: [Cd2Cl4(Hbm)2]n·nH2O (Hbm = 1H-benzimidazol-2-ylmethanol)

A new blue/green luminescent complex, [Cd2Cl4(Hbm)2]n·nH2O (Hbm = 1H-benzimidazol-2-ylmethanol), has been synthesized under hydrothermal condition, and characterized by X-ray crystallography, spectroscopy and thermoanalysis. The compound contains two isomeric polymeric chains with the difference in the coordination of the Hbm ligand to the central Cd(II) atom. The electronic structure and photoluminescent process was also investigated by means of density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. The calculation results demonstrate absorption peaks at 250, 261 and 287 nm are mainly (p, π) → π∗ with ILCT character, (p, σ) → d with LMCT character and p → d with LMCT character, respectively, and luminescent emission at 462 nm is LMCT transition.