Temperature‐Dependent Optical Activity Due to Quantized Molecular Rotation and Optical Rotation by Oriented Molecules
Temperature‐Dependent Optical Activity Due to Quantized Molecular Rotation and Optical Rotation by Oriented Molecules
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量子化分子旋转和定向分子旋光引起的温度依赖性旋光性
DOI：
10.1063/1.1673097
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发表时间：
1970
影响因子：
4.4
通讯作者：
Ying‐Nan Chiu
中科院分区：
文献类型：
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作者：
Ying‐Nan Chiu
关于旋光的经典著作已经处理了所有分子取向都是同等可能的随机系统。我们在这里考虑了量子力学旋转分子的旋光性。导出了对称和球顶分子的各个转动能级对旋光度的贡献。这些可以是属于C3、D3或T点群的不对称分子。的贡献被加权的玻尔兹曼分布的旋转水平，从而引起温度依赖性。这种依赖性在低温下将是显著的。结果表明，与经典随机系统一样，量子化转子的旋光来自于给定秩的电多极子与同秩的磁多极子的干涉.然而，由于依赖于旋转能级K，对于接近旋转跃迁频率的红外“光”的旋转，旋光度可以是0。
Classical works on optical rotation have dealt with random systems for which all molecular orientations are equally probable. We have considered here optical rotation by quantum mechanically rotating molecules. The contributions to optical rotation from the individual rotational levels of a symmetric‐ and a spherical‐top molecule have been derived. These may be asymmetric molecules belonging to the C3, D3, or T point group. The contributions are weighed by the Boltzmann distribution over the rotational levels, thus giving rise to temperature dependence. Such dependence will be significant at low temperatures. It is shown that, the same as for classical random systems, the optical rotation by quantized rotors comes from the interference of an electric multipole of a given rank with a magnetic multipole of the same rank. However, because of the dependence on the rotational energy level K, for the rotation of infrared “light” which is close to the frequency of a rotational transition, the optical rotation ma...