Five new Zn(II) and Cd(II) coordination polymers constructed by 3,5-bis-oxyacetate-benzoic acid: Syntheses, crystal structures, network topologies and luminescent properties

Five Zn(II) and Cd(II) coordination polymers, [Zn2(BOABA)(bpp)(OH)]·0.5H2O (1), [Cd3(BOABA)2(bpp)2(H2O)6]·2H2O (2), [Cd3(BOABA)2(2,2′-bipy)3(H2O)4]·5.5H2O (3), [CdNa(BOABA)(H2O)]2·H2O (4) and [Cd2(BOABA)(bimb)Cl(H2O)2]·H2O (5) (H3BOABA=3,5-bis-oxyacetate-benzoic acid, bpp=1,3-bi(4-pyridyl)propane, 2,2′-bipy=2,2′-bipyridine, bimb=1,4-bis(imidazol-1′-yl)butane), have been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and TG analyses. 1 is an uninodal 4-connected 2D square grid network based on binuclear zinc clusters. 2 is 2D wavelike layer structure and further linked by hydrogen bonds into the final 3D (5,6,6)-connected topology network. 3 is 3-connected 2D topology network and the 2,2′-bipy ligands decorate in two different types. 4 is a (4,8)-connected 2D topology network with heterocaryotic {Cd2Na2} clusters and BOABA3– ligands. 5 can be rationalized as a (3,10)-connected 3D topology network with tetranuclear {Cd4Cl2} clusters and BOABA3– ligands. Meanwhile, photoluminescence studies revealed that these five coordination polymers display strong fluorescent emission bands in the solid state at room temperature.