Shi Huancong, Roettger David C, East Allan L L
Department of Chemistry and Biochemistry, University of Regina, Regina, Saskatchewan S4S 0A2, Canada.
J Comput Chem. 2008 Apr 30;29(6):883-91. doi: 10.1002/jcc.20843.
Pericyclic reaction theory arose from ideas presented in 1965, based on orbital-energy correlation diagrams (Woodward and Hoffmann) and state-energy correlation diagrams (Longuet-Higgins and Abrahamson). Here we have used ab initio complete-active-space self-consistent field (CASSCF) calculations to generate such diagrams. First we present diagrams for the classic case of cyclobutene ring opening, to demonstrate agreement between the CASSCF results and the classic diagrams of both Woodward/Hoffmann and Longuet-Higgins/Abrahamson. Then we present diagrams for the more difficult cases of N(2) + photoexcited O(2), to produce either 2 NO or NNO + O. These N(2) + O(2) cases feature significant electron reorganization, for which elementary pencil-and-paper diagrams are less accurate. Finally, the benefits and limitations of such diagrams for predicting photochemistry are briefly discussed.
周环反应理论起源于1965年提出的观点，基于轨道能量相关图（伍德沃德和霍夫曼）和态能量相关图（朗格特 - 希金斯和亚伯拉罕森）。在此，我们使用从头算完全活性空间自洽场（CASSCF）计算来生成此类图。首先，我们给出环丁烯开环经典情况的图，以证明CASSCF结果与伍德沃德/霍夫曼和朗格特 - 希金斯/亚伯拉罕森的经典图之间的一致性。然后，我们给出更具挑战性的N(2) + 光激发O(2)情况的图，反应生成2 NO或NNO + O。这些N(2) + O(2)情况具有显著的电子重排，对于这种情况，简单的纸笔绘图不够准确。最后，简要讨论了此类图在预测光化学方面的优点和局限性。
