Coordination and Atom Transfer Chemistry at Surfaces of Polyoxometalate Anions

多金属氧酸盐阴离子表面的配位和原子转移化学

• 批准号: 8910921
• 负责人: Michael Pope
• 金额: $ 26.4万
• 依托单位: Georgetown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-06-15 至 1993-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8910921&HistoricalAwards=false
• 关键词: Coordination; Atom; Transfer; Chemistry; Surfaces

This award from the Inorganic, Bioinorganic and Organometallic Chemistry Program is in the area of inorganic chemistry and deals with large clusters of either molybdenum or tungsten atoms tied together by oxygen atoms, known as polyoxoanions. These species have become the focus of much attention recently as models of catalytic metal oxide surfaces, and are also under intensive investigation as highly active and versatile homogeneous catalysts. Development of reactivity on the surfaces of large polyoxoanions of molybdenum and tungsten in aqueous and nonaqueous solvents is seen as a way (a) to lead to new classes of compounds and homogeneous catalysts and (b) to model processes that are important in heterogeneous catalysis on metal oxides. "Activation" of polyanion surfaces is achieved by reduction, e.g. oxomolybdenum(VI) to aquomolybdenum(IV), or by synthesis of polyanions containing one or more lower-valent heteroatoms in place of W(VI) or Mo(VI). The activated polyanions bind a variety of neutral ligands, especially in anhydrous solvents. With appropriate choice of heteroatom and oxidation state, polyanion-ligand complexes undergo atom transfer, either to or from the ligand. This tendency toward atom transfer will be used to develop stoichiometric or catalytic oxygen atom transfer involving one or several adjacent sites on the polyanion surface. An extension of this work is expected to lead to rational synthesis of polyanions containing terminal multiply-bonded groups other than oxo oxygen (e.g. imido, hydrazido) with consequent novel reactivity.

该奖项由无机，生物无机和有机化学 化学课程是在无机化学领域， 处理钼或钨的大簇 由氧原子连接在一起的原子，称为多氧阴离子。 这些物种最近成为人们关注的焦点 作为催化金属氧化物表面的模型，并且也在 深入调查，高度活跃和多才多艺 均相催化剂 大型核反应堆表面反应性的发展 钼和钨在水溶液中的多氧阴离子， 非水溶剂被视为（a）产生新类别的一种方式 和（B）对化合物和均相催化剂进行建模 在多相催化中重要的过程， 金属氧化物聚阴离子表面的“活化”是通过 还原，例如氧代钼（VI）还原为钼水溶液（IV），或通过 含有一种或多种低价聚阴离子的合成 杂原子代替W（VI）或Mo（VI）。活性 聚阴离子结合各种中性配体，特别是在 无水溶剂。适当选择杂原子， 氧化态，聚阴离子-配体络合物经历原子 转移到配体或从配体转移。这种倾向 原子转移将被用来开发化学计量或 涉及一个或多个催化氧原子转移 聚阴离子表面上的相邻位点。延长该 本工作有望为聚阴离子的合理合成提供指导 含有除氧代以外的末端多键基团 氧（例如亚氨基、肼基），从而具有新的反应性。