Four Cu(I) cyanide coordination polymers, namely [Cu(L1)(CN)] n (1), [Cu 2 (L2)(CN) 2 ] n (2), [Cu 2 (L3)-(CN) 2 ] n (3) and [Cu 2 (L4)(CN) 2 ] n (4) (L1 = 4,4 0 -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 singlecrystal 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-HÁÁÁp stacking interactions. The fluorescence properties of the complexes and their catalytic activities for the degradation of Congo red azo dye in a Fentonlike process were investigated.