Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan.
Chemistry. 2013 Jul 15;19(29):9663-7. doi: 10.1002/chem.201204537. Epub 2013 Jun 3.
The mechanisms of the photochemical isomerization reactions were investigated theoretically by using a model system of 1,2-dihydro-1,2-azaborine with the CAS(6,6)/6-311G(d,p) and MP2-CAS-(6,6)/6-311++G(3df,3pd)//CAS(6,6)/6-311G(d,p) methods. Three reaction pathways, which lead to three kinds of photoisomers, have been examined. The structures of the conical intersections, which play a decisive role in such photorearrangements, were obtained. The thermal (or dark) reactions of the reactant species have also been examined by using the same level of theory to assist in providing a qualitative explanation of the reaction pathways. The model investigations suggest that the preferred reaction route for 1,2-dihydro-1,2-azaborine, which leads to the Dewar 1,2-dihydro-1,2-azaborine photoproduct, is as follows: reactant→Franck-Condon region→conical intersection→photoproduct. The results obtained allow a number of predictions to be made.
运用 1,2-二氢-1,2-氮杂硼烷模型体系，采用 CAS(6,6)/6-311G(d,p)和 MP2-CAS-(6,6)/6-311++G(3df,3pd)//CAS(6,6)/6-311G(d,p)方法，从理论上研究了光化学异构化反应的机理。考察了三条导致三种光异构体的反应途径。得到了在这类重排中起决定作用的锥形交叉点的结构。还采用相同的理论水平考察了反应物的热（或暗）反应，以帮助定性解释反应途径。模型研究表明，导致 Dewar 1,2-二氢-1,2-氮杂硼烷光产物的 1,2-二氢-1,2-氮杂硼烷的首选反应途径如下：反应物→Franck-Condon 区→锥形交叉点→光产物。所得结果可作出一些预测。
