Microwave, High-Resolution Infrared, and Quantum Chemical Investigations of CHBrF2: Ground and v4=1 States
Microwave, High-Resolution Infrared, and Quantum Chemical Investigations of CHBrF2: Ground and v4=1 States
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DOI：
10.1021/jp110510v
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发表时间：
2011-02-03
影响因子：
2.9
通讯作者：
Gauss, Juregen
中科院分区：
文献类型：
--
作者：
Cazzoli, Gabriele;Cludi, Lino;Gauss, Juregen
结合微波，红外和计算CHBrF 2的调查报告。对于振动基态，在毫米和亚毫米波区域的测量（CHBrF 2）-Br-79和（CHBrF 2）-Br-81提供旋转和离心畸变常数高达六次项以及超精细参数（四极耦合和自旋旋转相互作用常数）的溴核。后者的测定是通过记录光谱的亚多普勒分辨率，实现了通过兰姆浸渍技术，并支持光谱分析的高层次的量子化学计算在耦合簇水平。在这种情况下，相对论效应的重要性，这是6.5%的顺序，并包括在本工作中使用二阶直接微扰理论，需要强调准确的预测溴四极耦合常数。红外光谱的测量主要集中在（CHBrF 2）-Br-79的v（4）基频上。傅立叶变换研究使用同步辐射源提供了必要的分辨率的旋转结构的观察和分析。发现v（4）= 1态的光谱参数接近振动基态的光谱参数，表明v（4）带基本上不受微扰的影响。
A combined microwave, infrared, and computational investigation of CHBrF2 is reported. For the vibrational ground state, measurements in the millimeter- and sub-millimeter-wave regions for (CHBrF2)-Br-79 and (CHBrF2)-Br-81 provided rotational and centrifugal-distortion constants up to the sextic terms as well as the hyperfine parameters (quadrupole-coupling and spin-rotation interaction constants) of the bromine nucleus. The determination of the latter was made possible by recording of spectra at sub-Doppler resolution, achieved by means of the Lamb-dip technique, and supporting the spectra analysis by high-level quantum chemical calculations at the coupled-cluster level. In this context, the importance of relativistic effects, which are of the order of 6.5% and included in the present work using second-order direct perturbation theory, needs to be emphasized for accurate predictions of the bromine quadrupole-coupling constants. The infrared measurements focused on the v(4) fundamental band of (CHBrF2)-Br-79. Fourier transform investigations using a synchrotron radiation source provided the necessary resolution for the observation and analysis of the rotational structure. The spectroscopic parameters of the v(4) = 1 state were found to be close to those of the vibrational ground state, indicating that the v(4) band is essentially unaffected by perturbations.