Amatatsu Yoshiaki
Faculty of Engineering and Resource Science, Akita University, Tegata Gakuen-cho, Akita 010-8502, Japan.
J Phys Chem A. 2007 Jun 21;111(24):5327-32. doi: 10.1021/jp071092i. Epub 2007 May 27.
Ab initio complete active-space self-consistent field (CASSCF) and second-order Multireference Möller-Plesset perturbation (MRMP2) calculations were performed to examine the S1-S0 internal conversion of 6-cyanoazulene (6CNAZ). The azulene skeletons of 6CNAZ in S0 and S1 have features that resemble those of azulene. The stable geometry in S0 is characterized by (i) a C2v structure, (ii) an aromatic bond-equalized structure in which all the peripheral skeletal bond distances resemble an aromatic CC bond distance, and (iii) a single bond character of the transannular bond. The stable geometry in S1 is characterized by a nonaromatic C2v structure. Contrary to similarities of the stable geometries in S0 and S1 between 6CNAZ and azulene, the conical intersection (S1/S0-CIX) of 6CNAZ is different from that of azulene. The S1/S0-CIX of 6CNAZ takes a planar structure, whereas that of azulene takes a nonplanar structure in the seven-membered ring (Amatatsu, Y.; Komura, K. J. Chem. Phys. 2006, 125, 174311/1-8). On the basis of those computational findings, we predict the photochemical behavior of 6CNAZ in the S1-S0 internal conversion.
进行了从头算完全活性空间自洽场（CASSCF）和二阶多参考莫勒-普列斯塞微扰（MRMP2）计算，以研究6-氰基薁（6CNAZ）的S1-S0内转换。6CNAZ在S0和S1态的薁骨架具有与薁相似的特征。S0态的稳定几何结构具有以下特点：（i）C2v结构；（ii）一种芳香键均等化结构，其中所有外围骨架键长类似于芳香族碳-碳键长；（iii）跨环键的单键特征。S1态的稳定几何结构以非芳香族C2v结构为特征。与6CNAZ和薁在S0和S1态稳定几何结构的相似性相反，6CNAZ的锥形交叉点（S1/S0-CIX）与薁的不同。6CNAZ的S1/S0-CIX为平面结构，而薁的在七元环中为非平面结构（天田洋；小村健。《化学物理杂志》2006年，125卷，174311/1-8）。基于这些计算结果，我们预测了6CNAZ在S1-S0内转换中的光化学行为。
