J4 ›› 2009, Vol. 26 ›› Issue (3): 257-261.

• 光谱 •    下一篇

碘代烷烃分子的C-I断键机理研究

王骏1,张蓉蓉2,刘玉柱2,张冰2*   

  1. 1昆明学院物理科学与技术系,昆明650031;
    2中国科学院武汉物理与数学研究所, 波谱与原子分子物理国家重点实验室, 武汉 430071
     
  • 收稿日期:2009-01-13 修回日期:2009-01-14 出版日期:2009-05-28 发布日期:2009-05-07
  • 作者简介:王骏(1958-),研究生,工程师,昆明学院物理系教师。
  • 基金资助:

    国家自然科学基金(20673140)

C-I Bond Fission Mechanism of Alkyl Iodides

 WANG Jun, ZHANG Rong-Rong, LIU Yu-Zhu, Zhang Bing   

  • Received:2009-01-13 Revised:2009-01-14 Published:2009-05-28 Online:2009-05-07

摘要:

利用离子速度成像方法对碘代直链烷烃和环烷烃分子在267 nm下的光解断键机理进行了研究。实验分析了激发态I*(5p2P1/2)和基态I(5p2P3/2)的离子影像, 得到其对应速度、角度分布的各向异性参数值和相对量子产率和。实验发现碘代直链烷烃和环烷烃分子在吸收一个267nm的光子后,都发生快速的断键,直接解离生成激发态I*和基态I原子。与碘代直链烷烃相比,碘代环烷烃分子具有明显不同的角度分布特征,碘代环烷烃分子基态的值大于激发态。并且随着碳原子上所取代的烷基变重,有变小的趋势。

关键词: 光解动力学, 碘代烷烃, 离子速度成像, 共振增强多光子电离, 相对量子产率

Abstract:

The photodissociationmechanism of long-chain alkyl iodides and cyclic alkyl iodides at 267 nmwere studied using ion velocity imaging technique. Speed and angular distributions of corresponding photofragments were obtained by detecting ion images of I*(5p2P1/2) and I (5p2P3/2). Relative quantum yieldsand were also obtained. Iodine fragments in this study were both produced via direct and rapid dissociation of C-I bond after absorbing one photon of 267nm. Compared to long-chain alkyl iodides, cyclic alkyl iodides have obviously different characteristic of angular distributions which the value of anisotropy parameterfor I is bigger than that for I*. And as the alkyl group becomes heavier, will take place decreases.

Key words: hotodissociation dynamics, Alkyl iodides, Velocity map ion imaging, Resonance-enhanced multiphoton ionization, Relative quantum yields