Synthesis, structure and photocatalytic properties of two novel Cd (II) coordination polymers based on 1-[(2-methyl-1H-benzoimidazol-1-yl) methyl]-1H-benzotriazole

• Two new benzimidazole-based Cd(II) coordination polymers have been designed and synthesized. • The structure of polymers 1–2 was characterized adequately by X-ray study. • The photocatalytic study indicates that both two polymers possess excellent abilities in the degradation of methylene blue (MB) and rhodamine b (RhB). • The degradation efficiencies of polymer 1 for two dyes are both exceed 95%. Two new coordination polymers (CPs) [Cd(mbmb)I 2 ] n (1) and {[Cd 2 (mbmb) 3 I 2 (SCN) 2 ]·0.25(H 2 O)} n (2) have been synthesized with 1-[(2-methyl-1H-benzoimidazol-1-yl)methyl]-1H-benzotriazole (mbmb), and structurally characterized by X-ray single crystal diffraction analysis, elemental analysis, 1H NMR spectra and IR spectra. The X-ray analysis reveals that both polymers 1–2 crystallize in the triclinic space group P-1. Polymer 1 displays 1D chain structure and further connected through two different intermolecular π…π stacking interactions to form a 2D network. Polymer 2 possesses a 2D layer network, which is further extended into more stable 3D architecture. Moreover, polymers 1–2 were examined for photocatalytic degradation activities, and the result shows that they both present outstanding photocatalytic activities for the degradation of MB and RhB with remarkable efficiencies. For MB, the degradation efficiencies are 96.12% (1) and 95.59% (2); for RhB, the degradation efficiencies are 97.14% (1) and 94.51% (2). Polymer 1 shows higher photocatalytic performance in the degradation of MB and RhB.