Bicamphor: a prototypic molecular system to investigate vibrational excitons.
Bicamphor: a prototypic molecular system to investigate vibrational excitons.
复制标题
Bicamphor：研究振动激子的原型分子系统。
DOI：
10.1021/acs.jpca.5b02332
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
D. Lightner
中科院分区：
文献类型：
--
作者：
S. Abbate;G. Mazzeo;Silvia Meneghini;G. Longhi;S. Boiadjiev;D. Lightner
用振动圆二色谱（VCD）和红外光谱分别记录了内，内-双樟脑（1），外，外-双樟脑（2），内，外-双樟脑（3），3，3 '-双樟脑叉（4）和外，外-双硫代樟脑（5）的指纹谱和羰基伸缩谱。这些分子系统所具有的C2对称性（除了在一种情况下），以及它们有限的构象迁移率与定义明确的自由度，允许最佳测试的振动圆二色性激子手性（VCDEC）规则介绍了谷口和Monde。采用密度泛函理论计算不仅预测VCD和IR光谱的整个方面，而且还研究了VCDEC规则如何受到C-O伸缩之间的耦合以及C-O伸缩与其他振动模式之间的耦合的影响，以及围绕连接两个伸缩子的C-C键的旋转。评论提供的VCDEC方法的局限性和潜力，并在VCD光谱的其他区域，无论是在中红外或CH-伸缩区域的不同的振动激子的表现。
Vibrational circular dichroism (VCD) and IR spectra have been recorded in the fingerprint and carbonyl stretching regions for endo,endo-bicamphor (1), exo,exo-bicamphor (2), endo,exo-bicamphor (3), 3,3'-bicamphorylidene (4), and exo,exo-bis-thiocamphor (5). The C2 symmetry possessed by these molecular systems (except in one case), as well as their limited conformational mobility associated with well-defined degrees of freedom, allow for optimal test of the vibrational circular dichroism exciton chirality (VCDEC) rule introduced by Taniguchi and Monde. Density functional theory calculations are employed not only to predict the entire aspect of the VCD and IR spectra but also to study how the VCDEC rule may be impacted by the coupling between C═O stretchings and from C═O stretchings with other vibrational modes and by the rotation about the C-C bond connecting the two camphors. Comments are provided about the limitations and potentialities of the VCDEC method and about the manifestation of different vibrational excitons in other regions of the VCD spectra, either in the mid-IR or in the CH-stretching regions.