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Abstract: Four Fe(II/III) supramolecules, {[Fe(Hpdc)2(H2O)2]·2H2O} (1), [Fe(HImbc)2(H2O)2] (2), [Fe(phen)2(CN)2]·CH3CH2OH·2H2O (3), K[Fe(tp)2]·SO4 (4) (H2pdc = 2,5-Pyridinedicarboxylic acid, H2Imbc = 4,5-Imidazoledicarboxylic acid, phen = 1,10-phenanthroline, tp− = poly(pyrazolyl)borate), were synthesized by hydrothermal and room temperature stirring methods. They were characterized by single crystal X-ray diffraction, surface photovoltage spectroscopy (SPS), field-induced surface photovoltage spectroscopy (FISPS), electron paramagnetic resonance (EPR), UV–Vis absorption spectra (UV–Vis), infrared spectra (IR) and element analysis. The structural analyses indicate that complex (1) is a supramolecule with 2D structure connected by hydrogen bonds. Complex (2) is a supramolecule with hydrogen-bonded 3D structure. Complexes (3) and (4) are both 1D supramolecules connected by hydrogen bonds. The electronic state of central metal Fe(II) ions in complexes (1) and (2) is d6 with FeN2O4 coordination mode, lying in weaker distorted octahedral field. The electronic state of Fe(II) ion in complex (3) is d6 with Fe(CN)2N4 mode in the strong distorted octahedral field. The electronic state of Fe(III) ion in complex (4) is d5 with FeN6 mode, lying in the strong octahedral field. The micro-environment of Fe(II/III) ions in the four complexes is further investigated by EPR. The SPS of four complexes all exhibit photovoltage responses in the range of 300–700 nm. This indicates that they all possess certain photoelectric conversion capability. The effects of component, structure, type of ligands of the complexes, valence state and coordination micro-environment of the central metal ions on the SPS were discussed. Furthermore, the SPS and UV–Vis absorption spectra were interrelated. [Copyright &y& Elsevier]

Abstract: Three Ni(II) coordination complexes [NaNi(NTA)(H2O)] n (1), [Ni(pdc)2(Hppz)2]·H2O (2), [Ni(HL)2] (3) (H3NTA=nitrilotriacetic acid; ppz=piperazine; H2pdc=2,5-pyridinedicarboxylic acid; H2L=2-(1-piperazinl)-succinic acid) were obtained by hydrothermal synthesis method. The structures of the three complexes were determined by single crystal X-ray diffraction. Complex (1) is a 3D coordination polymer bridged by NTA3− groups; complex (2) is a mononuclear complex with ligands of pdc2− and Hppz+, forming a 3D supramolecule via hydrogen bonds; complex (3) is also a mononuclear complex with ligand of HL−, connected into a 3D supramolecule through hydrogen bonds. The photo-electric properties of complexes were investigated by surface photovoltage spectroscopy (SPS). The results of SPS show that the three complexes exhibit obvious photovoltage responses in the range of 300–800nm, which indicates that they all possess certain photo-electric conversion properties. Comparing and analyzing the SPS results of three complexes, it can be found that the component, structure and dimensionality of complex, the category of ligand, the species and number of the direct coordination atoms as well as change of the coordination microenvironment of central metal Ni(II) ion all affect obviously the SPS responses. The SPS and UV–Vis spectra of the complexes were interrelated. [Copyright &y& Elsevier]

Abstract: Four new heterometallic polymers, [NiCd(mal)2(H2O)2]n·2nH2O 1, [NiZn2(Hcit)2(H2O)2]n 2, [CoCd2(Hcit)2(H2O)2]n 3, [CoZn2(Hcit)2(H2O)2]n 4 (H2mal=malonic acid, H4cit=citric acid) were synthesized and characterized. The photoelectric properties of the polymers were discussed by the surface photovoltage spectroscopy (SPS). The structural analyses indicate 1 is a Ni–Cd heterometallic polymer with 3D structure bridged by the mal2– group. 2–4 are all heterometallic polymers with 2D structures bridged by the Hcit3– group. The results of SPS for the four polymers reveal that there are wide photovoltage response bands in the range of 300–800nm, which indicates that they all possess photoelectric conversion properties. By the introduction of the other metals, the SPS of heterometallic polymers are broadened obviously than the SPS of monometallic complexes. Moreover, the relationships between SPS and UV–Vis absorption spectra have been discussed. [Copyright &y& Elsevier]