Synthesis,Structure And Photo�electric Property Of A Series Of Co-M Hetero/ Homo�nuclear Coordination Polymers Based On Aromatic Carboxylic Acid Ligands

Ten coordination polymers have been designed and synthesized by the hydrothermal methods with Co?II??Mn?II??Cu?II?and Zn?II??Cd?II?as central metal and aromatic carboxylates?pyridine-dicarboxylic acid,benzenedicarboxylic acid,5-aminoisophthalic acid,benzene-1,2,4,5-tetracarboxylic acid,trans cinnamic acid etc?as main ligand.The structure and a lot of capability of the coordination polymers are characterized and researched.The formulas of the coordination polymers are listed as follows:?1?{[Co?H₂O?₆][CoZn₂?btec??2,6-pdc?₂?H₂O?₄]�8H₂O}_n?2?[CoZn₃?2,6-pdc?₄]_n?3?[CoMn?2,6-pdc?₂?H₂O?₅]�2H₂O?4?{[CoCd?1,3-bdc??2,3-pdc??H₂O?₂]�H₂O}_n?5?{[Co?aip??H₂O?]�2H₂O}_n?6?{[Mn?aip??H₂O?]�2H₂O}_n?7?[Mn?Cin?₂?H₂O?₂]_n?8?[Mn_2.5?HPO₄??PO₄??H₂O?₂]_n?9?[K₄Cu₂?ox?₄?H₂O?₄]_n?10?{[Cu₂?tar?₂?H₂O?₂]�3H₂O}_n?2,3-H₂pdc=pyridine-2,3-dicarboxylic acid,2,6-H₂pdc=pyridine-2,6-dicarboxylic acid,1,3-H₂bdc=1,3-benzenedicarboxylic acid,H₄btec=benzene-1,2,4,5-tetracarboxylic acid,H₂aip=5-aminoisophthalic acid,H₂ox=oxalic acid,H₂tar=tartaric acid,H₂cin=trans cinnamic acid?Crystal structure analysis shows that coordination polymers?1?⁴are novel Co-M[M=Zn?1?and?2?,Mn?3?,Cd?4?]heteronuclear coordination polymers,?5?is Co?II?-Co?II?homonuclear coordination polymer,?6?⁸are Mn?II?-Mn?II?homonuclear coordination polymers,?9?¹⁰are Cu?II?-Cu?II?coordination polymers.All the coordination polymers are determined,analyzed and assigned by IR,UV�Vis-NIR,surface photovoltage spectrum.Compare the SPS and the UV�Vis-NIR of the coordination polymers with each other and relating to the structure,the results are presented as follows:?1?The MLCT response band of Co-M heteronuclear coordination polymer is broader than homonuclear metal coordination polymer by the introduction of the M ions,the periods of M is different,the width of response band is also different.For example,?1?and?2?are Co-Zn heteronuclear coordination polymers,?4?is Co-Cd heteronuclear coordination polymer.Compare the SPS with each other,we find that the LMCT and MLCT response band of polymer?4?is broader than the coordination polymers?1?and?2?,which maybe caused by the difference at dispersion degree of 4d and 3d orbit in spatial distributing.the dispersion degree of 4d orbit is bigger,the response band is broader and stronger.?2?The SPS is influenced by the micro coordination enviroment of central metal.There are six-coordinated?CoO6 coordination mode?in the coordination polymer?1?,and there are six-coordinated?CoO₄N₂ coordination mode?in the coordination polymer?2?.Apparently,the symmetrical of the coordination polymer?2?is lower than the coordination polymer?1?,compare the SPS with each other,we find the response band aroused by d-d^*transition of the coordination polymer?2?is broader than the coordination polymer?1?.