• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >A Computational Study on the Mechanism of Intramolecular Oxo-Hydroxy Phototautomerism Driven by Repulsive pi sigma* State
【24h】

A Computational Study on the Mechanism of Intramolecular Oxo-Hydroxy Phototautomerism Driven by Repulsive pi sigma* State

机译：排斥pi sigma *态驱动分子内氧-羟基光互变异构机理的计算研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Potential energy(PE)surfaces of the lowest excited states of the 4(3H)-pyrimidinone/4-hydroxypyrimidine system were investigated with the aid of the CC2 and CASSCF methods of the electronic structure theory.These studies resulted in identification of a low-lying n sigma* state,which is dissociative with respect to the stretching of the N-H or O-H bonds in the oxo and hydroxy structures of the compound,respectively.After initial excitation to the lowest local n pi* and/or n pi* singlet states,the system can access the PE surface of the pi sigma* state by crossing a low barrier.It was computationally demonstrated that the system should evolve on the PE surface of the repulsive n sigma* state toward a broad seam of intersection with the PE surface of the ground state.At the intersection,the nonadiabatic transition to the ground electronic state takes place and the system can either evolve to a minimum of the initially excited tautomer or to the ground-state minimum of the other tautomer.The steps listed above provide a mechanism of photoinduced dissociation-association(PIDA)phototautomerism,experimentally observed for a number of monomelic molecules,structurally similar to 4(3H)-pyrimidinone/4-hydroxypyrimidine.This mechanism describes a new class of intramolecular photo tautomeric reactions driven by a repulsive n sigma* state.
机译：借助电子结构理论的CC2和CASSCF方法研究了4（3H）-嘧啶酮/ 4-羟基嘧啶体系最低激发态的势能（PE）表面。处于n sigma *状态，分别与化合物的oxo和羟基结构中的NH键或OH键的拉伸解离。初始激发后，最低的局部n pi *和/或n pi *单重态计算表明，该系统应在斥力n sigma *状态的PE表面上朝与PE表面相交的宽缝发展在相交处，发生了向绝电子状态的非绝热转变，并且系统可以演化为最初激发的互变异构体的最小值，也可以演化为另一个互变异构体的基态最小值。上面列出的步骤提供了一种光诱导解离缔合（PIDA）光互变异构的机制，实验观察到许多单体分子，结构上类似于4（3H）-嘧啶酮/ 4-羟基嘧啶。该机制描述了一类新的分子内光互变异构由斥力n sigma *状态驱动的反应。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号