Biradical-Like Reactive Intermediates

化学系的化学结构、动力学和机制B计划支持博尔德科罗拉多大学的Josef Michl教授研究以前未知的处于最低单重激发态的全烷基化低聚硅烷的松弛几何结构，这些结构是此类化合物中观察到的蓝色和绿色发射的原因。这些结构包含一个三角双锥几何结构的硅原子或两个四面体和三角双锥几何结构之间的硅原子，并且它们的硅原子携带五个而不是通常的四个“价”轨道。计算出的结构对硅纳米颗粒和所有饱和分子中的电子激发和电子传导有影响，但这需要实验验证。第二个独立项目涉及二十面体碳硼烷笼CB 11的化学。有人建议准备新的可逆阴离子/自由基夫妇的潜在利益作为新的空穴导体的组件，并检查这种笼的反应性时，它们包含一个裸露的硼顶点。拟议的研究与太阳能电池中的太阳能转换和光子学（例如，了解可能用于电视和计算机显示器的硅纳米粒子的光发射）特别相关。到目前为止，一些理论预测尚未得到验证，该奖项的工作将提供急需的实验验证。这项工作将为研究生和博士后研究人员提供合成有机化学和实验物理化学方面的优秀培训。

The Chemical Structure, Dynamics and Mechanisms B Program in the Division of Chemistry supports Professor Josef Michl of the University of Colorado at Boulder for investigation of previously unknown relaxed geometrical structures of peralkylated oligosilanes in their lowest singlet excited state, which are responsible for observed blue and green emissions in such compounds. These structures contain one silicon atom in a trigonal bipyramidal geometry or two silicon atoms at geometries half-way between tetrahedral and trigonal bipyramidal, and their silicon atoms carry five instead of the usual four "valence" orbitals. The calculated structures have implications for electronic excitation and electron conduction in silicon nanoparticles and all saturated molecules, but this requires experimental verification. A second independent project deals with the chemistry of the icosahedral carborane cage CB11. It is proposed to prepare new reversible anion/radical couples of potential interest as components of new hole conductors, and to examine the reactivity of such cages when they contain a naked boron vertex. The proposed research is especially relevant for solar energy conversion in solar cells and for photonics (for example, understanding light emission in silicon nanoparticles that may be used in television and computer displays). To date, several theoretical predications have yet to be tested, and the work in this award will provide much-needed experimental verification. The work will provide graduate students and postdoctoral research associates with excellent training in both synthetic organic and experimental physical chemistry.