Dipole forbidden, nuclear electric quadrupole allowed transitions and chirality: The broadband microwave spectrum and structure of 2-bromo-1,1,1,2-tetrafluoroethane
Dipole forbidden, nuclear electric quadrupole allowed transitions and chirality: The broadband microwave spectrum and structure of 2-bromo-1,1,1,2-tetrafluoroethane
复制标题
DOI：
10.1016/j.molstruc.2020.128277
复制
发表时间：
2020-09-15
影响因子：
3.8
通讯作者：
Grubbs, G. S.
中科院分区：
文献类型：
--
作者：
Isert, Joshua E.;Marshall, Frank E.;Grubbs, G. S.
本文报道了手性分子2-溴-1，1，1，2-四氟乙烷在6-18 GHz电磁波谱范围内的啁啾脉冲傅里叶变换微波谱。在Br-79和Br-81母体物种中的每个碳原子上都观察到六种同位素体，包括C-13同位素取代。所有的转动常数，四次离心畸变常数，和核四极耦合张量分量已被实验确定，并已报告。此外，自旋旋转组件M-aa，M-bb，和M-cc也被确定和报告。理论结构的物种已被确定和报告。C-C-Br骨架结构已经通过实验确定，实施Kraitchman单取代和Rudolph双取代分析，后者在文中解释。共观察到3440个跃迁，其中45个跃迁为电偶极禁戒跃迁。这些偶极禁戒跃迁已被确定，因为它们计划用于微波三波混频实验，以更好地理解它们的作用，如果有的话，在确定手性。所确定的核电四极耦合张量已对角化，并与类似的小烷烃物种，以作出推论的影响上的C-Br键。(c)2020 Elsevier B. V.保留所有权利。
The chirped pulse Fourier transform microwave spectrum of the chiral molecule 2-bromo-1,1,1,2- tetra fluoroethane has been observed in the 6-18 GHz region of the electromagnetic spectrum and is reported. Six isotopologues, including C-13 isotopic substitution at each carbon atom in both the Br-79 and Br-81 parent species have been observed in natural abundance. All rotational constants, quartic centrifugal distortion contants, and nuclear quadrupole coupling tensor components have been experimentally determined and have been reported. In addition, spin-rotation components M-aa , M-bb , and M-cc are also determined and reported. The theoretical structure of the species has been determined and reported. The C-C-Br backbone structure has been determined experimentally implementing both Kraitchman single and Rudolph double substitution analysis, the later being explained in the text. 3440 transitions total have been observed with 45 transitions being electric dipole forbidden. These dipole forbidden transi- tions have been identi fied as they are planned to be used in microwave three-wave mixing experiments in order to better understand their role, if any, in determining chirality. The determined nuclear electric quadrupole coupling tensor has been diagonalized and compared to similar small alkane species in order to make inferences on the effects of fluorination on the C-Br bond. (c) 2020 Elsevier B.V. All rights reserved.