Metallaborane Chemistry: From Small Heterobimetallaboranes to Large Metallaheteroboranes

密苏里大学圣彼得堡分校化学系劳伦斯·巴顿博士由化学部无机化学、生物无机化学和金属有机化学计划支持，用于金属硼烷化学研究。通过用不同的金属取代其中两个硼顶点，合成了由多面体硼烷衍生的杂双金属硼烷。早期过渡金属将与晚期金属结合，获得具有不同电子构型的金属物种。由于早期过渡金属络合物是良好的聚合催化剂，因此只含有这些金属的杂双金属硼烷将被制备并评价为硼烷齐聚催化剂。这项工作将扩展到将主族非金属原子结合到一种单金属硼烷中。将寻找通向大笼衍生物的路线，并将评估团簇取代过程的机制。硼烷形成了一系列具有规则结构的化合物和离子，其中硼-氢单元定义了多面体的顶点。硼支持这些笼状结构的能力是独一无二的。这个项目的目标是用非硼原子取代这种笼子中的一些顶点。将特别强调具有两种过渡金属的例子和具有过渡金属和主族非金属原子的例子。这些物种将被设计为可能的催化剂和探针，以确定硼烷中如何发生取代的细节。后一个目标对于制备特定形状和组成的新的金属硼烷是重要的。除了这个项目中将发现的新化学之外，博士后、研究生和本科生还将学习研究氢化硼所需的非常精确的实验技术。

Dr. Lawrence Barton, Chemistry Department, University of Missouri-St. Louis, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program of the Chemistry Division for research on metallaborane chemistry. Heterobimetallaboranes that are derived from polyhedral boranes by substituting two of the boron vertices by various metals will be synthesized. Early transition metals will be combined with late metals to obtain species with metals of different electronic configurations. Since early transition metal complexes are good polymerization catalysts, heterobimetallaboranes containing only these metals will be prepared and evaluated as borane oligomerization catalysts. The work will be extended to the incorporation of main group nonmetal atoms into a monometallaborane. Routes to large cage derivatives will be sought and the mechanisms of cluster substitution processes will be evaluated. Boranes form a series of compounds and ions with regular structures in which boron-hydrogen units define the vertices of polyhedra. The ability of boron to support these cage structures is unique. The object of this project is to substitute some of the vertices in such cages with non-boron atoms. Special emphasis will be placed on examples with two transition metals and ones with a transition metal and a main-group nonmetal atom. These species will be designed as possible catalysts and as probes to determine the details of how substitution occurs in the boranes. This latter objective is important to preparing new metallaboranes of specific shape and composition. In addition to the new chemistry that will be uncovered in this project, postdoctoral, graduate, and undergraduate students will be educated in the very precise experimental techniques required for the investigation of boron hydrides.