Transient infrared spectra of CH3SOO and CH3SO observed with a step-scan Fourier-transform spectrometer
Transient infrared spectra of CH3SOO and CH3SO observed with a step-scan Fourier-transform spectrometer
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DOI：
10.1063/1.3495765
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发表时间：
2010-11-14
影响因子：
4.4
通讯作者：
Lee, Yuan-Pern
中科院分区：
文献类型：
--
作者：
Chu, Li-Kang;Lee, Yuan-Pern
采用分步扫描傅里叶变换光谱仪与多程吸收池耦合，在260 K下测量了CH 3SSCH 3和O-2流动混合物在248 nm波长下辐照产生的瞬态组分的时间分辨红外吸收。在1397 +/- 1和1110 +/- 3 cm（-1）处观察到的两个瞬态谱带分别被暂时归属于syn-CH 3SO O的反对称CH 3-形变和O-O伸缩模;观察到的谱带轮廓表明，不太稳定的反CH 3SO O构象可能对这些吸收谱带有贡献。在稍晚的时期观察到的起源于1071 +/- 1 cm（-1）的谱带被归属于CH 3SO的S=O伸缩模，可能是通过CH 3SO的次级反应产生的。这些带符合令人满意的振动波数和旋转轮廓模拟的基础上的旋转参数的syn-CH 3SO O，反CH 3SO O，和CH 3SO预测密度泛函理论B3 LYP/aug-cc-pVTZ和B3 P86/aug-cc-pVTZ。后来在1170和1120 cm（-1）附近观察到的另外两个谱带被暂时分别指定为CH 3S（O）OSCH 3和CH 3S（O）S（O）CH 3;这两种物质可能是由CH 3SO的自反应产生的。还观察到了二次反应生成SO2的现象，并对可能的反应机理进行了讨论。(C)2010年美国物理学会。[doi：10.1063/1.3495765]
A step-scan Fourier-transform spectrometer coupled with a multipass absorption cell was employed to monitor time-resolved infrared absorption of transient species produced upon irradiation at 248 nm of a flowing mixture of CH3SSCH3 and O-2 at 260 K. Two transient bands observed with origins at 1397 +/- 1 and 1110 +/- 3 cm(-1) are tentatively assigned to the antisymmetric CH3-deformation and O-O stretching modes of syn-CH3SOO, respectively; the observed band contour indicates that the less stable anti-CH3SOO conformer likely contributes to these absorption bands. A band with an origin at 1071 +/- 1 cm(-1), observed at a slightly later period, is assigned to the S=O stretching mode of CH3SO, likely produced via secondary reactions of CH3SOO. These bands fit satisfactorily with vibrational wavenumbers and rotational contours simulated based on rotational parameters of syn-CH3SOO, anti-CH3SOO, and CH3SO predicted with density-functional theories B3LYP/aug-cc-pVTZ and B3P86/aug-cc-pVTZ. Two additional bands near 1170 and 1120 cm(-1) observed at a later period are tentatively assigned to CH3S(O)OSCH3 and CH3S(O)S(O)CH3, respectively; both species are likely produced from self-reaction of CH3SOO. The production of SO2 via secondary reactions was also observed and possible reaction mechanism is discussed. (C) 2010 American Institute of Physics. [doi:10.1063/1.3495765]