Millimeter wave spectrum of bromomethyl radical, CH2Br -: art. no. 134302
Millimeter wave spectrum of bromomethyl radical, CH2Br -: art. no. 134302
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DOI：
10.1063/1.1862619
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发表时间：
2005-04-01
影响因子：
4.4
通讯作者：
Saito, S
中科院分区：
文献类型：
--
作者：
Bailleux, S;Dréan, P;Saito, S
在180-470 GHz频率范围内，观测到溴甲基自由基的两个同位素物种（CH_2Br）-Br-79和（CH_2Br）-Br-81的基态电子态B-2（1）的转动光谱，对应于N=8-7到N=21-20的a型跃迁。该自由基是在自由空间电池中通过氯原子或氟原子对溴甲烷（CH 3Br）的氢提取而产生的。超精细结构，由于溴核已被解决在所观察到的光谱，旋转常数以及精细和超精细相互作用常数被准确地确定为两种同位素。（CH_2Br）-Br-79和（CH_2Br）-Br-81的惯性缺陷分别为0.028 96（20）和0.028 95（20）amu埃（2），表明其为平面结构。通过将HCH键角固定在124.5度，可以导出有效分子结构为r（0）（CBr）=1.848 A和r（0）（CH）=1.084埃。各种卤素取代的甲基自由基相对于这些自由基的平面性的分子结构的比较进行了讨论。(C)2005年美国物理学会。
The rotational spectra of the two isotopic species of the bromomethyl radical, (CH2Br)-Br-79 and (CH2Br)-Br-81, have been observed in their ground electronic state B-2(1) in the 180-470 GHz frequency region, corresponding to a-type transitions from N=8-7 to N=21-20. The radical was produced by hydrogen abstraction of methylbromide (CH3Br) either by chlorine or by fluorine atoms in a free space cell. Hyperfine structure due to the bromine nucleus has been resolved in the observed spectra, and the rotational constants as well as the fine and hyperfine interaction constants were accurately determined for both isotopomers. The inertial defect was determined to be 0.028 96(20) and 0.028 95(20) amu angstrom(2), for (CH2Br)-Br-79 and (CH2Br)-Br-81, respectively, suggesting a planar structure. By fixing the angle HCH bond angle at 124.5 degrees, an effective molecular structure can be derived as r(0)(CBr)=1.848 A and r(0)(CH)=1.084 angstrom. A comparison of the molecular structure of various halogen-substituted methyl radicals with respect to the planarity of these radicals is discussed. (C) 2005 American Institute of Physics.