Selective Evolution of Chemical Reactions on Excited Electronic Potential Energy Surfaces

有了这笔实验物理化学拨款，巴特勒博士将启动一系列研究，重点研究非绝热相互作用，这些相互作用主导着激发电子势能表面上化学反应的演变。这项工作将利用偏振发射光谱，与状态选择激光激发和产物检测技术相结合，测量分子解离过程中发射的光子的波长和偏振。这些研究旨在阐明能量允许的分解通道之间的分支如何对所访问的电子表面的性质以及随后的分子内能量转移过程以及在解离过程中与其他电子表面的非绝热相互作用非常敏感。这项工作的意义在于有可能通过光激发将化学反应产物控制到特定的电子态。许多例子包括吸附在表面的分子的光诱导反应，电子激发或开壳层原子或分子碰撞中的能量转移，以及气相或溶液中的双分子或单分子反应。由于这项工作探索了什么分子结构和动力学因素允许人们光诱导不会在热激发下发生的选择性化学反应，结果可能会推动合成化学新方法的发展。

With this grant in Experimental Physical Chemistry, Dr. Butler will initiate a series of studies which focus on investigating the nonadiabatic interactions which dominate the evolution of chemical reactions on excited electronic potential energy surfaces. The work will utilize polarized emission spectroscopy, which measures the wavelength and polarization of photons emitted during molecular dissociation, in conjunction with state-selective laser excitation and product detection techniques. The studies are designed to elucidate how the branching between energetically allowed decomposition channels can be critically sensitive to the nature of the electronic surface accessed, and the subsequent intramolecular energy transfer processes and nonadiabatic interactions with other electroinc surfaces during dissociation. The significance of the work lies in the potential for controlling the products of chemical reactions via photoexcitation to particular electronic states. Numerous examples include photoinduced reactions of molecules adsorbed on surfaces, energy transfer in collisions of electronically excited or open shell atoms or molecules, and bimolecular or unimolecular reaction in the gas phase or in solution. As the work explores what molecular structural and dynamical factors allow one to photoinduce a selective chemical reaction which would not occur upon thermal excitation, the results could advance the development of new methods of synthetic chemistry.