The Physical Properties And Synthesis Of Charge Transfer Complexes Based On Organic π-electron Donors And Hetero Polyoxometalate Salts

Huang yong hong Directed by Professor Jiang feng chi and Professor Liu cai mingOrganic conductors and superconductors have been attracted much attention since the discovery of the first organic conductor TTF-TCNQ in 1972. Up to now, hundreds of organic conductors have been synthesized, over 50 of which are superconducting. One promising way for designing high Tc superconductors is to increase the dimensionality by of organic donors. Which can be realized through not only preparing new organic donors but also changing new electron acceptors.Our research has focused on hybird molecular based on organic Ï€-electron donors and Anderson type hetero polyoxometalate salts containing organic groups. The main work are summarized as follows:(1)Two new Anderson type heteropolyoxometalate compounds, [N(C₄H₉)₄)]₃[MnMo₆O₁₈{(OCH₂)₃C-R}](R=NH₂,CH₂CH₃) , have been sucessfully synthesized.(2) Three new two-dimensional charge transfer complexes 1.[ET]₅{MnMo₆O₁₈[(OCH₂)₃CCH₂OH]₂}·5H₂O 2．[ET]₅{MnMo₆O₁₈[(OCH₂)₃C-CH₂CH₃]₂}·(2CH₃CN),3．[ET]₆{MnMo₆O₁₈[(OCH₂)₃CNH₂]₂}·(2CH₂Cl₂)(ET-bis(ethylenedithio)-tetrathiofuvaI en) denoted as I , II, and III respectively have been Prepared by electrocyrstallization techniques. Their structure have been determined by x-ray single crystal diffraction. The conductivity measurement shows that I is metallic condutor between 20k to 300k with room temperature conductivity constant 470 S cm-1 While compound II shows semiconductor behavior, its room temperature conductivity constant is 0.0208 S cm-1 and its active energy for about 0.03 eV.(3) The conductivity property of III and the magnetic properties of I , II, and III will be measured in the near future.Main innovative points of this reseach are listed as following:(1) Complexs I , II, and III are the first examples of cation-radical salts based on Anderson type (hetero) polyoxometalate salt and ET.(2) The organic groups in Anderson type hetero polyoxometalates can induce not only new Ï€-electron organic packing but also new stoichiometries as examplified by complexes I , II, and III.(3) Because of the a"' for organic packing of complex III, it is the first example of cation-radical salts based on polyoxometalate salt and ET .