| Eleven coodination complexes have been synthesized by the hydrothermal method withCo（Ⅱ）/Co（Ⅲ）, Ni（Ⅱ） and Cu（Ⅱ） as the center metal, organic aromatic polycarboxylic acidsand pyrazoles as main ligand. The structures were determined by single-crystal X-raydiffractometer, and identified all of which are single crystals. Their molecular formula are asfollows:[1] Co（Ⅱ）/Co（Ⅲ） complex [2] Ni（Ⅱ）/Cu（Ⅱ） complex（1）{[Co（phth）（phen）（H2O）].H2O}n（7）[Ni（pz）4（H2O）2].（H2btc）2.H2O（2）{[Co（btec）（H2O）4].（H2ppz）.（H2O）4}n（8）{[Ni2（pz）8（btec）].H2O}n（3）[Co（btec）0.5（pz）2]n（9）[Ni3（btc）2（H2O）8]n（4）[Co2（btec）（pz）6]n（10）[Ni（phth）（pz）2（H2O）]n（5）[Co2（2,6-pdc）2（H2O）5].（H2O）2（11）[Cu2（C8H7O2）4（C2H5OH）2]（6）[Co（phen）2（CO3）].（NO3）.H2O（H2phth=phthalic acid, phen=1,10-phenanthroline, H4btec=1,2,4,5-benzenetetra-carboxylic acid, ppz=piperazine, pz=pyrazole, H2pdc=pyridine-dicarboxylicacid, C8H8O2=methylbenzoic acid, H3btc=1,3,5-benzenetri-carboxylate acid）The IR, UV-Vis-NIR, surface photovoltage spectrum （SPS） and field-induced surfacephotovoltage spectrum （FISPS） of all the coordination polymers were analyzed and identified.The light-induced surface electron behaviors of polymers were studied by SPS, and thephoto-physics properties of polymers were determined and comparatively analized. The resultof SPS shows that there are obvious response band in the range of300-800nm underUV-Vis light-inducement indicating the photo-electric conversion signals were generated bythe light-inducement, which revealed that eleven polymers possess photo-electric conversionproperties. We found there are certain differences between the SPS response because ofdifferent structures by constrasting the SPS. And results are as follows:（1） The spatial structure of polymers influence the intensity of SPS. The higher of thedimension in polymers, the stronger of photovoltaic response intensity, normally. Forexemale,（2）>（4）>（5）. Coordination polymer （2） is a1D chain coodination complex basedon1,3,5-benzenetri-carboxylate acid and piperazine ligandand linked into a3D structure byhedrogen bonds. Coordination polymer （4） is a1D chain structure based on1,2,4,5-benzenetetra-carboxylic acid and pyrazole groups ligand, and linked into a2D structure by hedrogen bonds. Complex （5） is a3D structure which is completely linked by hedrogen bondswith2,6-pyridine-dicarboxylic acid ligand. Obviously, the bond energy of3D/2D structureconstructed by covalent bond and hydrogen bonds is stronger than that of3D structureconstructed all by hedrogen bonds, and provided more transitional ways for electron and holes.Thus the intensity of SPS is （2）>（4）>（5）.（2） The species and property of ligand has a significant effect on the SPS. SPS responseof coordination polymer was strengthen and widen with conjugated organic ligands,especially mixed organic ligands, obviously. For example, Co （Ⅱ） complexes, coordinationpolymers （2） is a complex with ligand1,2,4,5-benzenetetra-carboxylic acid and piperazine,complex （5） is a complex with ligand2,6-pyridine-dicarboxylic acid. Because of theintroduction of conjugated organic ligands piperazine, the SPS band intensity of complex （2）is not only stronger than complex （5）, but aslo wider than it, significantly. While in the Ni （Ⅱ）complexes, coordination polymers （9） is a complex with ligand1,3,5-benzenetetra-carboxylic acid, complex （10） is a complex with phthalic acid and pyrazolesligand, Because of the introduction of conjugated organic ligands pyrazole, the SPS bandintensity of complex （10） is not only stronger than complex （9）, but aslo wider than it,significantly.（3） The d electron configuration of central metal ion in complex has certain effect on theSPS number and position. For exemple, complexes（5） and （6） are both supramolecularcomplexes constructed by hydrogen-bonding, the central metal of complex （5） is Co （Ⅱ） ion（d7）, the central metal of complex （6） is Co （Ⅲ） ion （d6）, so performance for the complexes （6）contrast complexes （5） slightly redshift which is caused by d-d*transition of metal ion in SPS;Similarly, both coordination polymers （10）[Ni（phth）（pz）2（H2O）]nand [Co（phth）（pz）2]n（it issynthesized by others） are complexes with Ni（Ⅱ） and Co（Ⅱ） as central metal ion, respectively.There exist different response band number caused by d-d*transitions of center metal becauseof the differences between center metal and difference in SPS. It appears three surfacephotovoltaic response band caused by d-d*transitions in coordination polymer （10）,[Co（phth）（pz）2]nappears two surface photovoltaic response band caused by d-d*transitions. |
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