Series of Ln-metal organic frameworks: Photocatalytic performance and Hirshfeld surface analyses

Abstract Five new lanthanide metal–organic frameworks (Ln(III)-MOFs), namely, [Ln(L)(HL)(H2O)•1.5H2O]n (Ln(III) = Eu(1), Er(2), Dy(3), Gd(4) and Sm(5)) (H2L=5-(1H-1,2,4-triazol-1-yl)-1,3-benzenedicarboxylic acid) have been synthesized under hydrothermal condition and characterized by elemental analysis, IR spectra, powder X-ray diffraction and single crystal X-ray diffraction. Compounds 1-5 are formed at pH 3.5, which are isostructural and show 8-connected 3D framework with the bcu topological net and the Schlafli symbol of {424•64}. Interestingly, the deprotonated H2L ligands adopt respectively two different coordination behaviors (the fully deprotonated L2− and partially deprotonated HL−) to extend the framework. Additionally, compound 1 was successfully used as a photocatalyst for the degradation of organic dye rhodamine B (Rh B) under UV light irradiation and its possible reaction mechanism was also studied.