Syntheses, structures and luminescent properties of four novel Cd/Zn(II) complexes constructed from dicarboxylate and bis(imidazole) co-ligands

Four new complexes [Cd(1,3-bip)(1,4-bdc)]n (1), [Zn(1,3-bip)(1,4-bdc)]n (2), {[Cd(1,3-bip)(1,3-bdc)]·H2O}n (3) and {[Zn(1,3-bip)(1,3-bdc)]·2H2O}n (4) were prepared through hydrothermal reactions of Cd(II)/Zn(II) acetate with terephthalic acid (1,4-bdc)/isophthalic acid (1,3-bdc) and the flexible 1,3-bis(imidazole)propane (1,3-bip) co-ligands. All these complexes were structurally characterized by elemental analysis, FT-IR spectroscopy, powder XRD and X-ray single-crystal diffraction. Single crystal X-ray analysis revealed that complexes 1 and 2 are isostructural, which exhibit a 2-fold parallel interpenetrated 2D → 2D (4,4) net. Complex 3 features a 2D layer structure with a binodal (3,5)-connected topology. Complex 4 shows a 2D layer with a (4,4) topology. Furthermore, the photoluminescence properties in the solid state at room temperature and thermal behaviors of these complexes were also investigated.