物理化学学报 >> 2006, Vol. 22 >> Issue (09): 1079-1084.doi: 10.1016/S1872-1508(06)60048-X

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反式和顺式HOOOH的电子光谱的理论研究

王连宾;吴文鹏;张敬来;曹泽星   

  1. (河南大学精细化学与工程研究所, 河南 开封 475001; 厦门大学化学系固体表面物理化学国家重点实验室, 福建 厦门 361005)
  • 收稿日期:2006-01-15 修回日期:2006-04-06 发布日期:2006-09-04
  • 通讯作者: 张敬来 E-mail:zhangjinglai@henu.edu.cn

Theoretical Study on the Electronic Spectra of cis-HOOOH and trans-HOOOH

WANG Lian-Bin;WU Wen-Peng;ZHANG Jing-Lai;CAO Ze-Xing   

  1. (Institute of Fine Chemistry and Engineering, Henan University, Kaifeng 475001, P. R. China; State Key Laboratory for Physical Chemistry of Solid Surface, Department of Chemistry, Xiamen University, Xiamen 361005, P. R. China)
  • Received:2006-01-15 Revised:2006-04-06 Published:2006-09-04
  • Contact: ZHANG Jing-Lai E-mail:zhangjinglai@henu.edu.cn

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摘要： 用密度泛函方法(DFT)和全活化空间自洽场方法(CASSCF)以及耦合簇理论(CCSD)优化了反式和顺式HOOOH的平衡几何构型, 用DFT计算了HOOOH顺反异构化反应的势能曲线和谐振动频率. 用含时密度泛函理论(TD-DFT)和二阶全活化空间微扰理论(CASPT2)计算了反式和顺式HOOOH垂直激发能. 计算结果表明: (1)反式异构体比顺式异构体稳定; (2)两种稳定构型的异构化反应有两种路径; (3)对于垂直跃迁能最低的单态和叁态, 反式的垂直跃迁能比顺式的低; (4)在单激发态中, CASPT2方法预测的顺式HOOOH寿命最长的激发态为21A′′, 其跃迁能是167.43 nm, 寿命为 1.44×10−5 s; 反式HOOOH寿命最长的激发态为21A, 其跃迁能是165.52 nm, 寿命为 2.07×10−5 s.

关键词: DFT, CASPT2, HOOOH, 过渡态, 电子光谱

Abstract: Equilibrium geometries of cis-HOOOH and trans-HOOOH have been investigated using the density functional theory (DFT), complete active space self-consistent-field (CASSCF), and coupled cluster with single and double replacement (CCSD) approaches. The harmonic vibrational frequencies on the optimized geometries were calculated using the DFT theory. The potential energy curve of the isomerization between the trans-HOOOH and cis-HOOOH was obtained by DFT calculations. Time-dependent density functional theory (TD-DFT) and complete active space perturbation theory of second order (CASPT2) calculations have been performed to obtain the vertical excitation energies of selected low-lying singlet and triplet excited states. Computed results show that: (1) trans-isomer is more stable than cis-isomer; (2) there are two pathways of the conversion between the trans-HOOOH and cis-HOOOH; (3) the vertical excitation energies of the lowest singlet and triplet excited states in trans-HOOOH are lower than those in cis-isomer; (4) in the singlet excited states, 21A state in trans-HOOOH and 21A′′ state in cis-HOOOH have the longest lifetimes of 2.07×10−5 s and 1.44×10−5 s with the excitation energies of 165.52 and 167.43 nm, respectively.

Key words: DFT, CASPT2, HOOOH, Transition state, Electronic spectra