Design, structure and luminescent properties of a novel two-dimensional Cd(II) coordination polymer constructed from in situ generated 1-methyl-2-(3H-[1–3]triazol-4-yl)-1H-benzoimidazole

A cadmium (II) coordination polymer, namely {[Cd5(Ln)6Cl4]·2H2O}n (1, HLn = 1-methyl-2-(3H-[1–3]triazol-4-yl)-1H-benzoimidazole), has been constructed from in situ generated HLn under hydrothermal condition. The unsuccessful synthesis of 1 under similar synthesis condition using HLn as reactant suggests the in situ reaction is crucial for the assembly of the compound. Crystallography study reveals that 1 processes layer structure in which chains of [Cd3(Ln)4Cl4]2 − were connected by a pair of Cd ions. These layers further stack in an AAA model to form a 3D supramolecular framework and hydrogen bonding as well as π–π interaction were formed between adjacent layers to stabilize the framework. TGA indicates that 1 is highly thermally stable up to about 380 °C. The luminescence of 1 in the solid state which may be assigned to intraligand transition shows a blue shift of 16 nm compared to that of HLn·HCl.