Using a tunable diode-laser spectrometer, we have measured N(2)-broadening coefficients of 87 individual rovibrational lines in the P and R branches of the nu(3) band of methyl chloride (CH(3)(35)Cl) at 203.2 K. These lines with J values ranging from 2 to 22 and K from 0 to 6 are located in the range 711-751 cm(-1). Most of the collisional widths are obtained by modeling the spectral region from the superposition of overlapping Voigt or Rautian profiles. We have reviewed and completed previous measurements of N(2)-broadening coefficients at room temperature in the nu(3) band, in order to compare them to the low-temperature data. A semiclassical calculation, including electrostatic, induction, and dispersion energy contributions, has provided results that are in reasonable agreement with the experimental data at room temperature, but generally larger than the data at low temperature for small or medium J values. The temperature dependence of the collisional broadenings derived from a simple power law has been determined both experimentally and theoretically. Copyright 2001 Academic Press.

中文翻译：

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用二极管激光光谱法在低温下对氯甲烷进行 N2 加宽

使用可调谐二极管激光光谱仪，我们测量了 87 条独立振动线的 N(2) 展宽系数，这些线在甲基氯 (CH(3)(35)Cl) 的 nu(3) 波段的 P 和 R 分支中203.2 K。这些 J 值范围为 2 到 22，K 值范围为 0 到 6 的线位于 711-751 cm(-1) 范围内。大多数碰撞宽度是通过对重叠 Voigt 或 Rautian 轮廓叠加的光谱区域进行建模而获得的。我们已经回顾并完成了之前对 nu(3) 波段中室温下 N(2) 展宽系数的测量，以便将它们与低温数据进行比较。包括静电、感应和色散能量贡献的半经典计算提供的结果与室温下的实验数据合理一致，但对于中小 J 值，通常比低温下的数据大。由简单幂律导出的碰撞展宽的温度依赖性已通过实验和理论确定。版权所有 2001 学术出版社。