Structural and Stereochemical Effects in Organic Photochemistry

将在三个方面进行研究：(1)探索通过烷基丙叉、α-酰基取代的烷基丙叉或酰基丙叉双自由基进行的新的光化学反应。这项研究将考虑双自由基中间体的多样性及其对反应过程的影响。(2)分子内ı~(2+)-光环化反应的中间体--羰基取代双自由基的独立制备。(3)考察了三重态能量和特殊结构对杂芳烃氮三重态抽氢选择性的影响。将研究在吡啶、嘧啶和吡嗪中初级、次级和叔级氮的分子内提取。来自有机动力学项目的这笔赠款支持洛克菲勒大学威廉·C·阿戈斯塔教授的继续工作。含有光吸收基团以及碳-碳双键和三重键的分子将被辐照。将通过观察反应的最终产物来研究这些反应中的中间体。这些中间体将通过其他方法生成，以提供对中间体的电子状态和性质的更多了解。还将研究某些含氮分子的激发态能级和结构在氢的分子内转移中的作用。

Three research areas will be pursued: (1) New photochemical reactions that proceed by way of alkyl propargyl, alpha-acyl-substituted alkyl propargyl, or acyl propargyl biradicals will be explored. This study will include a consideration of the multiplicity of the biradical intermediates and the consequences to the course of reaction. (2) Independent preparation of carbonyl-substituted biradicals that are intermediates in intramolecular ı2+2!- photocyclization will be carried out. (3) The role of triplet energy and specific structure on the selectivity of hydrogen abstraction by heteroaromatic nitrogen triplets will be investigated. Intramolecular abstraction of primary, secondary, and tertiary nitrogen in pyridines, pyrimidines, and pyrazines will be studied. %%% This grant from the Organic Dynamics Program supports the continuing work of Professor William C. Agosta at Rockefeller University. Molecules that contain a light absorbing group, and in addition, a carbon-carbon double and triplet bond will be irradiated. The intermediates in these reactions will be investigated by observing the final products of the reactions. These intermediates will be generated by other methods to provide more insight into the electronic state and nature of the intermediates. The role of energetics of excited states and structure of certain nitrogen containing molecules in the intramolecular transfer of a hydrogen will be studied as well.