A new 1D coordination chain containing 4,4′-bi-1,2,4-triazole bridge: Synthesis, structure and optical properties

A new 1D coordination polymer [Cu(trtr)Cl2]n · 2nH2O (trtr = 4,4′-bi-1,2,4-triazole) was synthesized from the solution reaction of CuCl2 and trtr. The polymer is constructed by an inorganic skeleton chain [CuCl2]n with trtr anchoring on both sides like wing. The lattice water plays a significant role in the construction of the 3D super-molecular architecture by forming hydrogen bondings between trtr and water molecules. The fluorescence spectrum of the title compound features a dual-peak at 420 and 439 nm originating, respectively, from the π–π∗ intraligand transition and LMCT. Diffuse reflectance spectrum of the compound reveals the presence of optical gap of 2.45 eV, suggesting that the compound possesses semiconducting character.