New Methods for Polyhedral Borane Synthesis

宾夕法尼亚大学化学系Larry G. Sneddon博士在化学系无机、生物无机和有机金属化学项目的支持下，开发了新的通用方法，使多面体硼簇的系统、高产量制备成为可能。本项目将设计多种合成和修饰多面体硼化合物的新方法。这些反应包括：新型的碳和氮笼插入反应，涉及多面体硼阴离子对腈和极性乙炔的亲核攻击；金属催化多面体硼烷与乙炔、烯烃和/或一氧化碳的反应新型的硫原子插入反应生成了硫烷和二硫烷。第二个主要目标将是系统地探索将在项目的第一部分提供的簇的化学和应用。多面体硼烷是笼形分子，具有独特的化学键和不同寻常的性质。除了具有理论意义外，它们还被认为是获得新型陶瓷和聚合物的起始材料。然而，目前还没有经济地大量制备多面体硼烷的好方法。该项目的目的是开发新的、有效的合成方法来生成这些化合物。这将伴随着对新分子的化学性质的全面研究。这些研究将为多面体硼烷作为陶瓷和高分子材料的前驱体的实际应用奠定基础。

Dr. Larry G. Sneddon, Chemistry Department, University of Pennsylvania, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program of the Chemistry Division to develop new general methodologies that enable the systematic, high yield preparation of polyhedral boron clusters. In this project a variety of new approaches for the syntheses and modification of polyhedral boron compounds will be designed. These include: new types of carbon and nitrogen cage-insertion reactions involving the nucleophilic attack of polyhedral boron anions on nitriles and polar-acetylenes; metal-catalyzed reactions of polyhedral boranes with acetylenes, olefins, and/or carbon monoxide; and new types of sulfur-atom insertion reactions leading to thia- and dithiaboranes. A second primary goal will be a systematic exploration of the chemistry and applications of the clusters which will be made available by the first part of the project. The polyhedral boranes are cage shaped molecules which possess unique chemical bonding and unusual properties. Besides being of theoretical interest, they are thought to be starting materials from which novel ceramics and polymers may be obtained. However, there are presently no good ways in which large quantities of the polyhedral boranes can be prepared in an economical fashion. The aim of this project is the development of new, efficient synthetic methods for the generation of these compounds. This will be accompanied by comprehensive investigations of the chemistry of the newly available molecules. These investigations will set the stage for the practical applications of polyhedral boranes as precursors to ceramic and polymeric materials.