Three new copper(II) coordination polymers constructed from isomeric sulfo-functionalized phthalate tectonics: Synthesis, crystal structure, photocatalytic and proton conduction properties

Three new copper(II)-based coordination polymers, namely [Cu5(μ3-OH)4 (STP)2(4,4’-bipy)2(H2O)2]·4H2O (CTGU-20), [Cu2(μ2-OH)(SIP)(1,4′-bib)2] (CTGU-21) and [Cu2 (SIP)(4,4′-bibp)2(HCOO)]·3H2O(CTGU-22), (STP ​= ​2-sulfoterephthalate, SIP ​= ​5-sulfoisophthalate, 4,4’-bipy ​= ​4,4’-bipyridine, 4,4′-bibp ​= ​4,4’-bis(imidazolyl)biphenyl and 1,4′-bib ​= ​1,4-bis(1-imidazoly) benzene) have been prepared by two less-developed isomeric sulfo-functionalized phthalate ligands under solvothermal conditions and characterized by PXRD, single crystal X-ray diffraction analysis and thermogravimetric analysis.CTGU-20 exhibits a 3D pillared-layer framework constructed from a unique 1D Cu4O8–CuO4 rod packing unit generated by four μ3-OH groups and pyridyl/carboxylicate mixed linkers. While, CTGU-21 shows a 3D pillared-layer framework extended by Cu2(μ2-OH)(SIP) layers and 1,4′-bib pillars. When 1,4′-bib was replaced by longer 4,4′-bibp, CTGU-22 is obtained, which features a 2D bilayer structure bridged by double 4,4′-bibp ligand. Remarkably, complexes CTGU-20, CTGU-21 and CTGU-22 show promising photocatalytic activities toward the degradation of Rhodamine B(RhB), methyl blue(MB) and 9,10-bis (phenylethynyl)anthracene(BPEA). Moreover, the proton conductivity for three complexes were also studied.