Structural and Stereochemical Effects in Organic Photochemistry

(1)探索以烷基丙炔、α -酰基取代烷基丙炔或酰基丙炔双自由基为途径进行的新型光化学反应。本研究将包括考虑双自由基中间体的多样性及其对反应过程的影响。(2)独立制备羰基取代双自由基，作为分子内ı2+2！-进行光循环。(3)研究了三重态能量和特定结构对杂芳烃氮三重态吸氢选择性的影响。将研究吡啶、嘧啶和吡嗪中伯氮、仲氮和叔氮的分子内提取。这项来自有机动力学项目的拨款支持了洛克菲勒大学威廉·c·阿戈斯塔教授的继续工作。含有光吸收基团的分子，加上碳碳双键和三重键，就会被照射。这些反应中的中间体将通过观察反应的最终产物来研究。这些中间体将通过其他方法生成，以便更深入地了解中间体的电子状态和性质。本文还研究了激发态的能量学和某些含氮分子的结构在氢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.