Flexible 3,5-bis(3,4-dicarboxyphenoxy) benzoic acid based coordination polymers as photocatalysts for the sensitive photodegradation of methylene blue

Abstract

Three new coordination polymers (CPs) with formulas [Cu(H2O)(H3L)]n (1), [Cu4(HL)2(H2O)4·2.5H2O]n (2) and [Cu2(H2O)2(HL)·CH3CN]n (3) (H5L = 3,5-bis(3,4-dicarboxyphenoxy) benzoic acid), have been synthesized and characterized. 1 exhibit a 2D supramolecular framework built by the hydrogen bond interactions between adjacent chains. 2 shows a linear tetranuclear {Cu4(COO)4} SBU-based 2D (3,6)-c net with a point symbol of {42.6}2{44.69.82}. 3 possesses a uninodal 4-connected 2D sql topology framework with the point symbol (44·62). The photocatalytic degradation properties of the three CPs are investigated. Significantly, 3 is a promising photocatalyst for the degradation of methyl blue (MB) compared to others. Moreover, the possible photodegradation mechanism was proposed and explored. The active species involved in the degradation of MB have been assessed using trapping experiments.