Solution and Gas-Phase Photochemistry Involving Multiple and Delocalized Excited States

将研究离域和/或多激发态反应的分子的光化学和光物理性质，特别强调评估通过键和通过空间相互作用的相对作用。在溶液中，将研究多功能底物，利用天线生色团或离域激发来激活远端基团，这些基团在紫外线中是透明的或弱吸收的，或者是吸收的，但可以通过天线选择性地激活。将特别注意：(1)通过类固醇骨架的电荷转移传输，(2)三官能团中的能量转移，以及(3)西格玛键合继电机制促进虚拟轨道混合的潜在作用。在气相方面，研究将重点放在新发现的硫酮的诺里什第二类化学上。来自有机动力学项目的这笔资金支持普渡大学莫里森教授的继续工作。分子中的官能团会被光吸收激发，并将研究这种能量转移到分子中其他官能团的机制。一个特别令人担忧的问题是确定能量是通过债券还是通过空间转移的。在另一阶段的研究中，将研究独特的含硫化合物的光化学和光物理性质。

Photochemical and photophysical properties of molecules which react from delocalized and/or multiple excited states will be studied, with a particular emphasis on evaluating the relative roles of through-bond and through-space interactions. In solution, polyfunctional substrates will be studied, utilizing antenna chromophores or delocalized excitation to activate distal groups which are transparent or weakly absorbent in the ultraviolet or are absorbent but may be selectively activated through the antenna. Special attention will be given to: (1) charge transfer transmission through the steroid frame-work, (2) energy transfer in trifunctional steroids, and (3) the potential role of sigma bonded relay mechanisms to facilitate virtual orbital mixing. In the gas-phase, studies will emphasize the newly discovered Norrish Type II chemistry of thioketones. %%% This grant from the Organic Dynamics Program supports the continuing work of Professor Morrison at Purdue University. Functional groups in molecules will be excited by light absorption and the mechanism by which this energy is transferred to other functional groups in molecules will be studied. A particular concern will be to determine if the energy is transferred through bonds or through space. In another phase of the research, unique photochemical and photophysical properties sulfur containing compounds will be investigated.