Syntheses, structures and surface photo-electric properties of Cd(II)-btec coordination polymers

Two Cd (II) coordination polymers [Cd3Na2(btec)(2)(H2O)(2)](n) (1) and {[Cd3Na2(btec)(2) center dot (H2O)(2)] center dot 4H(2)O}(n)(2) (H(4)btec = 1,2,4,5-benzenetetracarboxylic acid) were synthesized by hydrothermal method.. The structures were determined by single crystal X-ray diffraction. Structural analyses show that the asymmetric units of polymers 1 and 2 contain two crystallographically unique Cd(II) ions with six-and eight-coordinate, respectively, and they possess 3D structures bridged by btec(4-) groups. The structure differences between them are that the coordination environment around Na(I) ions is different and polymer 2 has lattice water molecules. The photo-electric properties of the two polymers were investigated by surface photovoltage spectroscopy(SPS). The results of SPS show that the two polymers exhibit obvious photovoltage responses in the range of 300-500 nm, which indicates that they all possess certain photo-electric conversion properties. The SPS and UV-Vis spectra of the polymers were interrelated, and XRD patterns and TG curves of the two polymers were measured and analyzed.