| The research work of this dissertation is directed by the idea of lacunary directed synthesis that the lacunary sites of various polyoxometalate?POM?precursors may act as the structure directing agents and induce different metal ions to form novel clusters which was first summarized by our group under the practice and experience of the exploration on the metal-oxo cluster recent years.We introduced different kinds of tungsten-oxo lacunary precursors and the second type of metal ions into the hydrothermal reaction system,expecting to obtain novel high-nuclear metal substituted tungstate-oxo clusters,aggregates.Under the guidance of the above mentioned idea and the hard work,we successfully obtained five series of novel metal substituted tungsten-oxo clusters?about twenty compounds?,which were characterized by spectroscopies,structures,thermal and relevant properties.The successful syntheses of these compounds not only enrich the structural type and synthetic idea of tungsten-oxo cluster chemistry,but also provide a novel route for the development of tungsten-oxo cluster chemistry.Series 1:Six discrete organic N-ligands functioned hexa-manganese-substituted POMs?H3deta?4[(SiW9O34)2Mn4IIIMn2IIO4?H2O?4]?8H2O?3-1?,[H2en]5[(B-?-SiW9O34)2Mn4IIIMn2IIO4?H2O?2?Hen?2]?8H2O?3-2?,[H2ppz]4[H21,3-dap]2[(B-?-SiW9O34)2Mn4IIIMn2IIO4?H2O?2?ppz?2]?6H2O?3-3?,H2[H2ppz]4[(B-?-SiW9O34)2Mn4IIIMn2IIO4?H2O?2?Hppz?2]?8H2O?3-4?,[H2ppz]3[H3deta]2[(B-?-SiW9-O34)2Mn4IIIMn2IIO4?ppz?4]?12H2O?3-5?and[H2ppz]2[H2en]2[(B-?-SiW9O34)2Mn4IIIMn2IIO4?Hppz?4]?en·10H2O?3-6?have been isolated under hydrothermal conditions.magnetic measurements reveal that3-6 exhibits SMM behavior.Optical band gap measurement of 3-1 to 3-6 suggests that they have the semiconductive characteristics.Series 2:Two organic-inorganic hybrid tetra-cobalt-substituted POMs H3{[Co?en?2]0.5[Co?en?2?H2O?]2[Co?en??H2O?]2[Co4?en?(B-?-SiW9O34)2]}·9H2O?4-1?,?H2ppz?2[Co?mea?2?2,2'-bpy?]2[Co4?Hppz?2(B-?-PW9O34)2]·8H2O?4-2?have been isolated under hydrothermal conditions.compound 4-1exhibits a 2-D sheet structure,in which the en molecules and[Co?en?2]2+cations as the linkers.In compound 4-2 three types of organic amine ligands are included.Series 3:Other TM-substituted organic-inorganic hydrid POMs H4?H21,6-HMD?2{[Zn?H2O?]6(?-SbW9O33)2}·14H2O?5-1?,{[Zn?Hen?6](?-SbW9O33)2}·12H2O?5-2?,H4?H2en?2[Mn2.25?H2O?4(B-?-SbW9.75O35)]2·12H2O?5-3?,?H2en?4{?WO2?2[Ni?Hen??H2O?]2(B-?-SbW9O33)2}·12H2O?5-4?,have been made by degrading antimoniotungstate precursor.5-3 and 5-4 are extended structures constructed by 1-D chains and 2-D layers respectively.Two organic-inorganic hybrid di-chromium-substituted POMs?H2en?3[??2-OH?{Cr[NH?CH2COO?2]}2(?-PW11O39)]·6H2O?5-5?,H4?H2en?4[{??2-OH?Cr[NH?CH2COO?2]}2(?-PW11O39)]2·25H2O?5-6?all consisit of??2-OH?{Cr[NH?CH2COO?2]}2(?-PW11O39)clusters.Optical band gap measurement of 5-1 to 5-4 suggests that they have the semiconductive characteristics.Series 4:Four organic-inorganic hybrid POMs H5?H2en?3[Fe2La(?-PW10O37)2?Tart?]·9H2O?6-1?,H5?H2en?3[Fe2Ce(?-PW10O37)2?Tart?]·7H2O?6-2?H3?H2en?4[Fe2Sm(?-PW10O37)2?Tart?]·25H2O?6-3?,H3?H2en?4[Fe2Tb(?-PW10O37)2?Tart?]·21H2O?6-4?have been obtained.In 6-1 to 6-4 transition metal and lanthanide ion co-exist in the vacant site of divacant[?-PW10O37]9-.6-3 and 6-4 exist a rare inorganic–organic hybrid supramolecular nanotube built from the organic-inorganic hybrid 3d-4f POM units.6-1 to 6-4 exhibit photochromism properties.The successful syntheses of these novel compounds further confirms that not only the hydrothermal technique is an effective synthetic method in the POM field,but also the utilization of multi-dentate ligands is an effective strategy to design and make metal-subsitituted POMs,which endows us with a great opportunity and challenge in exploiting and making more novel organic-inorganic hybrid POM derivatives by means of the appropriate choice of different lacunary POM precursors and various organic ligands. |
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