物理化学学报 >> 2012, Vol. 28 >> Issue (05): 1094-1100.doi: 10.3866/PKU.WHXB201203062

理论与计算化学 上一篇    下一篇

2-苯基苯并噁唑的光解反应

李会学, 王晓峰, 李志锋, 朱元成   

  1. 天水师范学院生命科学与化学学院, 新型分子材料设计与功能省教育厅重点实验室, 甘肃天水 741001
  • 收稿日期:2012-01-06 修回日期:2012-03-05 发布日期:2012-04-26
  • 通讯作者: 李会学 E-mail:li_hx2001@126.com
  • 基金资助:

    天水师范学院中青年教师科研基金资助项目(TSA1116).

Photolysis Reaction of 2-Phenylbenzo[d]oxazole

LI Hui-Xue, WANG Xiao-Feng, LI Zhi-Feng, ZHU Yuan-Cheng   

  1. Key Laboratory for New Molecule Design and Function of Gansu Education Department, College of Life Science and Chemistry, Tianshui Normal University, Tianshui 741001, Gansu Province, P. R. China
  • Received:2012-01-06 Revised:2012-03-05 Published:2012-04-26
  • Contact: LI Hui-Xue E-mail:li_hx2001@126.com
  • Supported by:

    The project was supported by the Research Fund of Tianshui Normal University for Young College Teachers, China (TSA1116).

摘要: 聚对苯撑苯并二噁唑(PBO)纤维对光较为敏感, 在紫外光照射下会发生降解. 本文研究了该纤维的单体2-苯基苯并噁唑(PO)的初级光化学反应机理. 当PO分子吸收一个光子而跃迁到第一激发态后, 克服25.59 kJ·mol-1能垒而越过过渡态, 此时噁唑环打开, 且两个苯环形成大约90°的二面角而得到产物, 该产物可进一步与空气中的水发生次级反应. 计算结果表明在第一激发态上噁唑开环反应很容易, 但在基态势能面并没有发现噁唑的开环路径. 分子中的原子(AIM)的计算结果与上述分析过程相吻合.

关键词: 理论研究, 光解反应, 2-苯基苯并噁唑

Abstract: The temperature-resilient, high tensile-strength fiber poly[p-phenylene benzobisoxazole] (PBO) is light-unstable and it degrades under ultraviolet radiation. In this paper we study the photolytic mechanism of the PBO monomer, 2-phenylbenzo[d]oxazole (PO). Following absorption of a photon and excitation into the first excited state (S1), the molecule overcomes an energy barrier of 25.59 kJ·mol-1 to enter the transition state; the oxazole ring is then opened and both benzene rings form a dihedral angle of about 90° to obtain the product, which undergoes further addition reaction with water. Calculations reveal that ring-opening is easily achieved in the potential surface of S1. However, the pathway through which the oxazole ring opens in the ground state remains obscure. The topological properties of these compounds are in good agreement with the expected bond orders and the photolytic mechanism.

Key words: Theoretical study, Photolysis reaction, 2-Phenylbenzo[d]oxazole

MSC2000: 

  • O641