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

Three new coordination polymers (CPs) with formulas [Cu(H2O)(H3L)](n) (1), [Cu-4(HL)(2)(H2O)(4)center dot 2.5H(2)O](n) (2) and [Cu-2(H2O)(2)(HL)center dot 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 {Cu-4(COO)(4)} SBU-based 2D (3,6)-c net with a point symbol of {4(2)center dot 6}(2){4(4)center dot 6(9)center dot 8(2)}. 3 possesses a uninodal 4-connected 2D sql topology framework with the point symbol (4(4)center dot 6(2)). 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 photo-degradation mechanism was proposed and explored. The active species involved in the degradation of MB have been assessed using trapping experiments.