New Cd(II) and Zn(II) coordination polymers showing luminescent sensing for Fe(III) and photocatalytic degrading methylene blue

Abstract

Hydrothermal reactions of the 1,5-bis(2-methylbenzimidazol-1-yl)pentane (L) and different polycarboxylates with cadmium(II)/zinc(II) acetate provided two new coordination polymers (CPs), namely, [Cd2(L)2(hfpd)]n (CP 1) and [Zn(L)(tbta)]n (CP 2) (H4hfpd = 4,4′-(hexafluoroisopropylidene)diphthalic acid, H2tbta = tetrabromoterephthalic acid). Both of the CPs were characterized by single crystal X-ray diffraction and elemental analysis, infrared spectroscopy, powder X-ray diffraction, and thermogravimetric analyses. CP 1 possesses a two-dimensional (2D) 3,4L13 network with point symbol of {4·62}2{42·62·82}. CP 2 is a 3D sqc182 framework with the point symbol {66}. The solid-state ultraviolet emission by two CPs was quenched by Fe3+ in aqueous solution with detection limit 0.31 μM and 0.85 μM (S/N = 3) for CP 1 and CP 2, respectively. Further, CP 1 and CP 2 show promising photocatalytic activities for degradation of the methylene blue (MB) in water.