Designed Assembly, Structual Characterization And Properties Of Polyoxometalate Clusters With Amnioacid Components

In this thesis, based on trivacant Keggin phosphotungstate,Na2MoO4·2H2O (NH4)6Mo7O24·4H2O, K2Te03, NaSeO3, As2O3, CuCl2·2H2O and aminoacids as the initial materials, by controlling pH, reaction time, reaction temperature and molar stoichiometry of reactants, we have prepared five novel organic-inorganic hybrid polyoxometalate (POM) derivatives with amnioacid components under hydrothermal conditions or in the conventional aqueous solution. These compounds have been charactered by elemental analyses, IR spectra, IR, UV spectra and X-ray sing-crystal diffraction. Their thermogravimetric, electrochemical, magnetic and ferroelectric propertiesha have been invstigated. The succefull syntheses of these POM-based clusters with amnioacids not only enrich the structural diversities of POM-based derivatives, but also extend the research domains of amnioacid chemistry and POM chemistry. This thesis can be devided into five sections to interpretate the work during my master study:Section1:The developments of chiral polyoxometalate clusters and aminoacid-based polyoxometalate clusters have been chiefly summarized.Section2:Two unique1-D organic-inorganic hybrid copper-aminoacid-complex bridging heteropolymolybdates [Cu(arg)2]2[(CuO6)Mo6O18(As3O3)2]-4H2O (1) and [Cu(arg)2]3[TeMo6O24]·8H2O (2)(arg=L-arginine) have been prepared.1stands for the first1-D chain organic-inorganic hybrid arsenomolybdate constructed from lantern-shaped [(CuO6) Mo6O1g(As3O3)2]4-units through dinuclear [Cu2(arg)4]4+connectors whereas2represents an unprecedented1-D chain organic-inorganic hybrid telluromolybdate built by Anderson-type [TeMo6O24]6-fragments via trinuclear [Cu3(arg)6]6+bridges. Their magnetic properties have been quantitatively analyzed and simulated by means of the magnetic exchange models of di-Cu and tri-Cu complexes. The results indicate that1and2exhibit the weak antiferromagnetic interactions. Furthermore, the solid-state electrochemical and electrocatalytic properties of1have been carried out by cyclic voltammetry. The results show that1displays apparent electrocatalytic activities towards the reduction of nitrite and bromate.Section3:Two isostructural chiral organic-inorganic hybrid heteropolymolybdates K2[TeMo6O21(O2C-CH(NH3)-CH2-OH)3]·6H2O (3), K2[SeMo6O21(O2C-CH(NH3)-CH2-OH)3]·6H2O (4) have been isolated, in which serine ligands are incorporated into the skeletons of heteropolymolybdates. Both have been characterized by elemental analyses, IR spectra, IR, UV spectra and X-ray sing-crystal diffraction. Because both crystallize in chiral space group P212121, the optical activity of them has been evaluated by circular dichroism spectra.Section4:An organic-inorganic hybrid mono-SmⅢ substituted phosphotungstate KNa3[HPro]7[Sm(α-PW11O39)2]·Pro·18H2O (5)(Pro=D-proline) has been synthesized by making use of chirality transfer method. The molecule of5consists of a classical1:2-type [Sm(a-PW]1039)2]11-fragment and eight free D-proline components. It should be pointed out that the synergistic action between the in-situ formed chiral [Sm(a-PW11O39)2]11-fragment and chiral D-proline components results in the formation of the chiral5. Its photoluminescent and ferroelectric behavior has been measured.Section5:Two new organic-inorganic hybridgermanotungstate-based copper-lanthanide heterometallic derivatives KNa2H7[enH2]3[Cu(en)2(H2O)]2[Cu(en)2]2{Cu(en)2[Eu (α-GeW11O39)2]2}·13H2O (6) and Na2H4[Cu(en)2(H2O)]2[Cu(en)2]6[Cu(en)2]{Cu(en)2[La(a-GeW11O39)2]2}·12H2O (7) have been hydrothermally synthesized.6exhibits the1-D chain motif built by tetrameric{[Cu(en)2(H2O)]2[Cu(en)2]2{Cu(en)2[Eu(α-GeW11O39)2]2}}16-moieties through square antiprismatic K+cations while7displays the1-D architecture made by tetrameric [[Cu(en)2]6[Cu(en)2]{Cu(en)2[La(a-GeW11O39)2]2}]10-units via octahedral [Cu(en)2]2+cations. The photoluminescent and electrocatalytic properties of6have been probed.