Semibullvalenes as Transition State Probes: Homoaromaticity and Matrix Effects

有了这个奖项，有机和高分子化学计划支持爱达荷州大学的理查德五威廉姆斯教授的工作。 这项研究将涉及研究的分子预测的理论计算，以表现出难以捉摸的性质的同芳香性。 先前制备的几种分子在溶液（凝聚相）中没有表现出这种性质，但现在已经表明，溶剂极性对所选体系（semibullvalenes和barbaralanes）中的科普重排（决定同芳香性的关键）的屏障具有深远的影响。 基质效应的基态的bisannelated semibullvalenes的结构将被检查，基质效应的机制将被阐明，并根据这些研究准备最佳的系统。 如果成功的话，这些稠合的半牛稀将允许直接的光谱观察（什么是有效的）周环化学反应的过渡态。 这项研究的更广泛影响包括培训年轻科学家，他们不仅将获得敏感分子合成方面的广泛经验，而且还将接触到广泛的最先进技术以及实验与理论之间的协同作用。 这项研究的一个特点是与世界各地的团体合作，这将使学生接触到跨学科和合作研究。 此外，对这些分子的研究将大大推进对复杂电子相互作用的理解，并将为这些反应的性质和基质效应提供相当多的见解。 控制分子内的电子相互作用，特别是通过基质效应，具有显著的基本兴趣和重要性，并且具有在催化、传感和材料性质（例如，非线性光学效应）。

With this award, the Organic and Macromolecular Chemistry Program supports the work of Professor Richard V. Williams of the University of Idaho. This research will involve the study of molecules predicted by theoretical calculations to exhibit the elusive property of homoaromaticity. Several previously prepared molecules were shown not to exhibit this property in solution (condensed phases) but it has now been shown that solvent polarity has a profound influence on the barrier to the Cope rearrangement (crucial in determining homoaromaticity) in selected systems (semibullvalenes and barbaralanes). Matrix effects on the structure of the ground states of bisannelated semibullvalenes will be examined, the mechanism of the matrix effects will be elucidated and optimum systems will be prepared based on these studies. If successful, these annelated semibullvalenes will allow the direct spectroscopic observation of (what is effectively) the transition state for a pericyclic chemical reaction. The broader impacts of this research include the training of young scientists who will not only gain broad experience in the synthesis of sensitive molecules, but will also be exposed to a wide range of state-of-the-art techniques and to the synergy between experiment and theory. A feature of this research is collaborations with groups around the world which will expose the students to interdisciplinary and collaborative research. In addition, study of these molecules will greatly advance the understanding of the complex electronic interactions and will provide considerable insight into the nature of these reactions and into matrix effects. Controlling the electronic interactions within a molecule, particularly through matrix effects, is of significant fundamental interest and importance and has the potential for applications in catalysis, sensing and materials properties (e.g., non-linear optical effects).