Two 3-D coordination polymers based on 5-sulfoisophthalic acid sodium salt: synthesis, crystal structures and photocatalytic reduction of CO2

Two new coordination polymers constructed from 5-sulfoisophthalic acid sodium salt (NaH2SIPA) and Co or Cu cations, [Co3(SIPA)2(4,4′-bpy)4(H2O)6]·4H2O (1) and [Cu6O3(HSIPA)3(4,4′-bpy)6(H2O)3]·7H2O (2), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), IR spectroscopy, thermogravimetric analysis, UV-Vis spectroscopy, and elemental analysis. Compound 1 represents a twofold-interpenetrating 3-D framework based on Co, SIPA, and 4,4′-bipyridine ligands with a qzd topology. Different from 1, compound 2 shows a 3-D self-penetrating framework based on Cu, HSIPA, and 4,4′-bipyridine ligands. Furthermore, the photocatalytic performance in reduction of CO2 of 1 under visible light was investigated.