Second moments and rotational spectroscopy
Second moments and rotational spectroscopy
复制标题
DOI：
10.1016/j.jms.2016.06.001
复制
发表时间：
2016-07-01
影响因子：
1.4
通讯作者：
Fournier, Joseph A.
中科院分区：
文献类型：
--
作者：
Bohn, Robert K.;Montgomery, John A., Jr.;Fournier, Joseph A.
尽管使用微波光谱法确定分子结构是一项成熟的技术，但对数据分析仍然存在简单但有力的见解，但这些见解并未得到普遍重视。本文总结了二阶（或平面）矩的三种应用，这些应用可以快速、轻松地提供有关分子结构的见解和结论，而这很难从分子的旋转常数中获得。如果分子具有对称平面，则群二阶矩可以验证该性质并确定哪些基团位于该平面上。公共组为二阶矩贡献可预测的值。本研究考察了 CH2/CH3、CF2/CF3、异丙基和苯基对分子常数的贡献和可转移性。相关分子的结构可以使用它们的二阶矩进行严格比较。第三种应用适用于任何分子，即使是那些结构仅具有单位对称元素的分子，也可以确定键长和角度，从而准确地再现实验确定的二阶矩、旋转常数和惯性矩。不需要近似最小二乘法。 (C) 2016 年，爱思唯尔公司出版
Although determining molecular structure using microwave spectroscopy is a mature technique, there are still simple but powerful insights to analysis of the data which are not generally appreciated. This paper summarizes three applications of second (or planar) moments which quickly and easily provide insights and conclusions about a molecule's structure not easily obtained from the molecule's rotational constants.If the molecule has a plane of symmetry, group second moments can verify that property and determine which groups are located on that plane. Common groups contribute predictable values to second moments. This study examines the contribution and transferability of CH2/CH3, CF2/CF3, isopropyl, and phenyl groups to molecular constants.Structures of related molecules can be critically compared using their second moments.A third application to any molecule, even those whose structures have only the identity symmetry element, determines bond lengths and angles which exactly reproduce experimentally determined 2nd moments, rotational constants, and moments of inertia. Approximate least squares methods are not needed. (C) 2016 Published by Elsevier Inc.