Fe(II) coordination polymers: Structures and surface photoelectric properties

Two new Fe(II) coordination polymers, [Fe(dcbp)(H2O)2]n 1 and [Fe(pdc)(H2O)2]n∙nH2O 2 (H2dcbp = 4,4′-dicarboxy-2,2′-bipyridine, H2pdc = pyridine-2,5-dicarboxylic acid), were synthesized by hydrothermal method and characterized by IR, UV–Vis absorption spectra, elemental analysis, electron paramagnetic resonance spectra and X-ray single crystal diffraction. The surface photoelectric properties of Fe(II) coordination polymers were discussed emphatically by surface photovoltage spectroscopy (SPS). The structural analyses indicate that 1 is 3D coordination polymer bridged by dcbp2− groups and 2 is 2D layer structure bridged by pdc2− groups. The results of SPS show that there are photoelectric responses in the range of 300–550 nm, which reveals that they all possess photoelectric conversion properties. By the comparison and analysis, it is found that the dimension, species of ligands and coordination micro-environment of the Fe(II) ions should affect the results of the SPS. The SPS were associated with the UV–Vis absorption spectra.