In situ construction of four copper(I) cyanide coordination polymers: crystal structures, fluorescence and catalytic properties

Four Cu(I) cyanide coordination polymers, namely [Cu(L1)(CN)] n (1), [Cu2(L2)(CN)2] n (2), [Cu2(L3)(CN)2] n (3) and [Cu2(L4)(CN)2] n (4) (L1 = 4,4′-bis(1,2,4-triazolyl-1-yl)-biphenyl, L2 = 1,4-bis(5,6-dimethylbenzimidazole)butane, L3 = 1,3-bis(2-methylbenzimidazole)propane, L4 = 1,5-bis(5,6-dimethylbenzimidazole)pentane), were synthesized and structurally characterized by X-ray single-crystal diffraction. The cyanide anions in these complexes were generated in situ by cleavage of the C–C bond of acetonitrile under hydrothermal conditions. Complex 1 possesses a 1D infinite ladder-like chain structure, while complexes 2, 3 and 4 exhibit similar 2D (6,3) networks. Both 3 and 4 are further extended into 3D supramolecular frameworks by C–H···π stacking interactions. The fluorescence properties of the complexes and their catalytic activities for the degradation of Congo red azo dye in a Fenton-like process were investigated.