Three new Coordination Polymers based on a 1-(3,5-dicarboxy-benzyl)-1H-pyrazole-3,5-dicarboxylic acid ligand: Synthesis, crystal structures, magnetic properties and selectively sensing properties

Abstract

Three new Coordination Polymers (CPs), namely [Co2(dpb)(dipe)(H2O)2]n (1), [Zn2(dpb)(dipe)(H2O)2]n (2) and {[Co2(dpb)(bib)2(H2O)]·H2O}n (3), where H4dpb = 1-(3,5-dicarboxy-benzyl)-1H-pyrazole-3,5-dicarboxylic acid, dipe = (E)-1,2-di(pyridin-4-yl)ethene, bib = 1,4-di(1H-imidazol-1-yl)benzene, have been synthesized hydrothermally and characterized. Single-crystal XRD data analysis reveals that 1 and 2 are isomorphic, and possessing a (3,4,5)-connected net with a Schläfli symbol of (4·62)(4·65)(42·65·83), Complex 3 presents a (4,4,4)-connected 3-nodal 3D net with {4·62·83}{4·63·82}{64·82}. Also, we systematically examined the fluorescence sensing responses of 2 to small solvent molecules and metal ions. Notably, complex 2 can act as a potential promising fluorescence sensor for sensing acetone and Fe3+ ion with high selectivity and sensitivity. Meanwhile, we have investigated the magnetic behaviors of complexes 1 and 3 with dinuclear Co(II) centers, revealing antiferromagnetic behavior in 1 and 3.