Syntheses, Structures And Properties Of Organic-inorganic Hybrid Polyoxotungstate-based Transition-metal/Lanthanide-metal Derivatives

In the present dissertation, three series of novel organic–inorganic hybrid transition-metal/lanthanide（TM/Ln） substituted polyoxotungstates （POTs） have been successfully synthesized under hydrothermalconditions, when the systems containing polyoxotungstate precursors, TM and/or Ln cations wereemployed in the presence of multidentate organic ligands as structure-stabilizing agents. These compoundswere characterized by spectroscopies, crystal structures, thermal analyses, luminescence and magneticproperties. The successful preparations of these compounds not only indicate that we overcame thecompetition reaction between TM cations and Ln cations, discover the appropriate reaction conditionsbetween TM cations and Ln cations and polyoxometalate precursors, thus realize the interdisciplinary ofLn chemistry, TM chemistry and polyoxometalate （POM） chemistry, but also provide a novel researchroute for the sustainable development of POM chemistry.1. Two organic–inorganic hybrid CuII–LnIIIheterometallic arsenotungstates [Cu（H2O）5]0.5[Cu（dap）2（H₂O）]₂[Cu（dap）₂]₃[Tb(α-AsW₁₁O₃₉)₂]·4H₂O （1） and [Cu（en）₂H₂O][Cu（en）₂]_1.5Na₃H₃[Er(α-AsW₁₁O₃₉)₂]·5H₂O（2）（en=ethylenediamine, dap=1,2-diaminopropane） have been hydrothermally synthesized. The mainfeature of1exhibits the rare1D zigzag chain based on [Tb（α-AsW11O39）2]11subunits and [Cu（dap）2]2+connectors.2displays an infrequent2D architecture established by [H₃Er(α-AsW₈₁₁O₃₉)₂] units and[Cu（en）₂]²⁺bridges. The TGA curve indicates the weight loss of1can be divided into two steps, while2exhibiting three weight-loss steps.2. Five organic–inorganic hybrid CuII–LnIIIheterometallic phosphotungstates [Cu（dap）2（H2O）][Cu（dap）₂]_3.5H₂[La(α-PW₁₁O₃₉)2_]·6H₂O （3）,[Cu（dap）₂（H₂O）]_0.5[Cu（dap）₂]4H₂[Nd(α-PW₁₁O₃₉)₂]·4H₂O （4）,[Cu（dap）₂（H₂O）]₂[Cu（dap）₂]_3.5[Eu(α-PW₁₁O₃₉)₂]·6H₂O （5）,[Cu（dap）₂（H₂O）][Cu（dap）₂]₄.5[Sm(-PW₁₁O₃₉)₂]·4H₂O （6） and [Cu（dap）₂（H₂O）][Cu（dap）₂]_4.5[Er(-PW₁₁O₃₉)₂]·4H₂O （7） have been successfully isolated. The2D sheets of3–7are constructed by1:2-type bis（undecatungstophosphate）lanthanate [Ln(α-PW₁₁O₃₉)₂]₁1units and [Cu（dap）₂]²⁺connectors. Magnetic susceptibility measurements indicate that4–7demonstrate weak antiferromagnetic couplings. The photoluminescence measures reveal that5showsobvious luminescence signal.3. An novel organic–inorganic hybrid paratungstate [enH₂]₂[Cu（en）₂]₃[H₂W₁₂O₄₂]·6H₂O （8） and anorganic-inorganic hybrid monocopper substituted Dawson-type arsenotungstate （H₂en）_0.5[Cu（en）₂]_0.5 {[Cu（en）₂（H₂O）]₂[Cu（en）₂](α1-As₂W₁₇CuO₆₁)}·8H₂O （9） have been synthesized. The structure of8consistsof [H₂W₁₂O₄₂]¹⁰clusters and [Cu（en）22]+linkers that exhibits an interesting6-connected3-D topologicalnet.9displays an interesting1-D chain constructed from [α-As2W17CuO61]8subunits by means ofcommon oxygen atoms and [Cu（en）₂)₂]⁺bridges. The TG curve indicates that the weight loss of8and9canbe divided into three steps.