Cobalt(II) and silver(I) coordination polymers containing flexible bis (benzimidazol-1-yl)hexane ligands: synthesis, crystal structures, sensing and photocatalytic properties

Two new ternary metal coordination polymers (CPs), namely, {[Co-2(BTC)(L)]center dot 0.25H(2)O}(n) (1) and [Ag(HIPA)(L)](n) (2) (H4BTC = 1,2,3,4-butanetetracarboxylic acid, H(2)IPA = isophthalic acid, L = 1,6-bis(5,6-dimethylbenzimidazol-1-yl)hexane) were hydrothermally synthesized and characterized by elemental analysis, infrared spectroscopy, single-crystal X-ray diffraction, and powder X-ray diffraction (PXRD). 1 exhibits unusual 2D network with point symbol {4(3).6(3)}(2){4(6).6(6).7(3)}. 2 possesses 1D chain structure which is further extended into a 3D supramolecular network via O-H center dot center dot center dot O hydrogen-bonding and pi-pi stacking interactions. 1 and 2 can selectively detect benzaldehyde (BZH), Fe3+ (just 1) and Cr2O72- (just 2) ions in water via the luminescence quenching process. Furthermore, the photocatalytic activities of two CPs were evaluated for degradation of methylene blue (MB) and methyl violet (MV) under UV irradiation.