Syntheses, structures and photoelectric properties of a series of Cd(II)/Zn(II) coordination polymers and coordination supramolecules

Five Cd(II)/Zn(II) complexes [Cd(1,2-bdc)(pz)2(H2O)]n (1), [Cd1Cd2(btec)(H2O)6]n (2), [Cd(3,4-pdc) (H2O)]n (3), [Zn(2,5-pdc)(H2O)4]·2H2O (4) and {[Zn(2,5-pdc)(H2O)2]·H2O}n (5) (H2bdc=1,2-benzenedicarboxylic acid, pz=pyrazole, H4btec=1,2,4,5-benzenetetracarboxylic acid, H2pdc=pyridine-dicarboxylic acid) were hydrothermally synthesized and characterized by single-crystal X-ray diffraction, surface photovoltage spectroscopy, XRD, TG analysis, IR and UV–vis spectra and elemental analysis. Structural analyses show that complexes 1–3 are 1D, 2D and 3D Cd(II) coordination polymers, respectively. Complex 4 is a mononuclear Zn(II) complex. Complex 5 is a 3D Zn(II) coordination polymer. The surface photoelectric properties of complexes were investigated by SPS. The results indicate that all complexes exhibit photoelectric responses in the range of 300–600 nm, which reveals that they all possess certain photoelectric conversion properties. By the comparative analyses, it can be found that the species and coordination micro-environment of central metal ion, the species and property of ligands affect the intensity and scope of photoelectric response.