Polyborane Syntheses and Reactions

宾夕法尼亚大学化学系Larry Sneddon博士在化学系无机、生物无机和有机金属项目的支持下，开发了新的通用方法，用于系统地、高产地合成聚硼烷化合物和聚合物。本研究将为聚硼烷的合成和改性提供新的离子液体基方法；金属催化的聚硼烷氢硼化、脱氢硼化和烯基聚硼烷复分解反应；以及通过早期金属催化的烯基聚硼烷聚合和钌催化的烯基聚硼烷开环复分解聚合（ROMP）反应生成聚（有机聚硼烷）聚合物的途径。这些研究将强调新反应的发现和对其基本步骤和控制因素的理解的发展。新的反应将使系统合成重要的新型烷基和烯基聚硼烷、碳硼烷和连接聚硼烷分子化合物，以及具有潜在技术用途的新型杂化“聚硼烷-无机”和“聚硼烷-有机”聚合物材料成为可能。了解金属-聚硼烷相互作用的性质对发现和控制新的金属催化反应具有重要意义；因此，本项目的进一步中心目标是更好地理解聚硼烷和金属聚硼烷的结构、键合、反应机制和性质。聚硼烷化合物具有重要的性质，其应用范围从抗癌剂、高温聚合物、燃烧速率调节剂、核废料萃取剂、陶瓷前体和弱配位阴离子。然而，由于无法有效地合成和修饰这些化合物，这些和其他潜在用途的开发以及该领域的进一步科学发展受到严重阻碍。显然需要合理的、选择性的、高收率的反应方法。该项目将培养有创造力和技能的年轻科学家，其中将包括妇女和代表性不足的少数民族。

Dr. Larry Sneddon, Department of Chemistry, University of Pennsylvania, is supported by the Inorganic, Bioinorganic, and Organometallic Program of the Chemistry Divisionto develop new general methodologies for the systematic, high-yield syntheses of polyborane compounds and polymers. The proposed work will result in new ionic-liquid based methods for the synthesis and modification of polyboranes; metal-catalyzed polyborane hydroboration, dehydrogenative-borylation, and alkenylpolyborane metathesis reactions; and routes to poly(organopolyborane) polymers via both early metal catalyzed alkenylpolyborane polymerization and ruthenium-catalyzed alkenylpolyborane ring opening metathesis polymerization (ROMP) reactions. The studies will emphasize the discovery of new reactions and the development of an understanding of their fundamental steps and controlling factors. The new reactions will enable the systematic synthesis of important new alkyl- and alkenylpolyborane, carborane and linked-polyborane molecular compounds, and totally new types of hybrid "polyborane-inorganic" and "polyborane-organic" polymeric materials that have potential technological uses. Understanding the nature of metal-polyborane interactions is of fundamental importance to the discovery and control of new metal catalyzed reactions; therefore, a further central goal of this project is to achieve a better understanding of the structures, bonding, reaction mechanisms, and properties of both polyboranes and metallapolyboranes.Polyborane compounds have important properties that give rise to applications ranging from uses as cancer agents, high temperature polymers, burn rate modifiers, extractants for nuclear wastes, ceramic precursors and weakly coordinating anions. However, the exploitation of these and other potential uses, as well as the further scientific development of the field, has been seriously hampered by the inability to efficiently synthesize and modify such compounds. There is a clear need for rational, selective, high yield reaction methods. The project will educate creative and skilled young scientists, which will include women and under represented minorities.