| 2-氢吡喃分子光激发开环反应机理的理论研究 |
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| 引用本文： | 吕玲玲a,闫尔弟b,王小芳a,王永成c,戴国梁d.2-氢吡喃分子光激发开环反应机理的理论研究[J].中国化学,2008,26(7):1195-1200. |
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| 作者姓名： | 吕玲玲a 闫尔弟b 王小芳a 王永成c 戴国梁d |
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| 作者单位： | a天水师范学院生命科学与化学学院，甘肃 天水741001 ;b临洮东关镇医院，甘肃 临洮 730500 ;c西北师范大学化学化工学院，甘肃 兰州 730070 ;d复旦大学化学系，新型催化材料重点实验室，上海 200433 ; |
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| 摘 要： | 用完全活性空间多组态(CASSCF)方法对2-氢吡喃分子光激发开环反应机理进行了研究。利用价键理论(VB)和自然键道分析(NBO)探究了沿能量最低反应途径电子的重新分布情况。计算结果表明从S0-Min p®p*垂直激发到Franck-Condon点后很容易弛豫到S1-Min，经较低的势垒到达圆锥交叉点S1/S0。而S1/S0与S1-Min相比能量低0.63eV。这样体系沿非绝热最低反应途径从激发单重态经交叉点S1/S0很容易得到产物S0-Prod。
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| 关 键 词： | 2-氢吡喃分子 价键理论(VB) 自然键道分析(NBO) 光开环反应机理 |
| 收稿时间： | 2007-11-3 |
| 修稿时间： | 2008-2-26 |
Theoretical Study on the Photochemical Ring Opening Process of 2H‐pyran |
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| Ling‐Ling LÜ,Er‐Di YAN,Xiao‐Fang WANG,Yong‐Cheng WANG,Guo‐Liang DAI.Theoretical Study on the Photochemical Ring Opening Process of 2H‐pyran[J].Chinese Journal of Chemistry,2008,26(7):1195-1200. |
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| Authors: | Ling‐Ling LÜ Er‐Di YAN Xiao‐Fang WANG Yong‐Cheng WANG Guo‐Liang DAI |
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| Institution: | 1. Chengguan Health Center of Lintao, Lintao, Gansu 730500, China;2. College of Life Science and Chemistry, Tianshui Normal University, Tianshui, Gansu 741001, China;3. College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, China;4. Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Shanghai 200433, China |
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| Abstract: | A theoretical study of the reaction path for the photo‐ring‐open mechanism for a model system 2H‐pyran has been carried out using a CASSCF method. To monitor the electronic rearrangements along the minimum energy pathway (MEP), the electronic structures were analyzed using valence bond (VB) theory and natural bond orbital (NBO) analysis. Calculated results show that the S0‐Min, the absorption of the initial excitation, promotes the system to the S1 excited state with a (π‐π??) character. From the S1‐Min, a low‐barrier path leads to an S1/S0 conical intersection. The energy of the S1/S0 crossing is located 0.63 eV below the S1‐Min. Thus, the initial movement of the nuclei will lead the system through the S1/S0 crossing to the ground state of the S0‐Prod in a very efficient nonadiabatic path along the MEP. |
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| Keywords: | 2H‐pyran valence bond theory natural bond orbital (NBO) the ring opening mechanism |
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