We have recently analyzed the broadband millimeter-wave rotational spectrum of chloroform CH³⁵Cl₃ in the v₃ = v₆ = 1 (E symmetry) and v₆ = 2 (A₁ + E) excited vibrational states . In the present work, we have used the same spectrum (recorded in the 150 - 330 and 360–660 GHz spectral regions) for a rotational analysis of the v₂ = 1 and v₃ = 2 A₁ states of the same molecule, together with a new analysis of the v₅=1 (E) fundamental vibration.

For the v₂ = 1 state (A_1, near 677 cm⁻¹), the body of assigned data comprises 392 rotational transitions. The corresponding frequencies were fitted within an isolated-level model, with a standard deviation of 36.4 kHz, and the obtained parameters are in good agreement with the previous IR work.

For the v₃ = 2 vibrational state (A₁, near 734 cm⁻¹), a total of 351 rotational transitions were assigned. Their fit was improved by inclusion of a second-order Coriolis coupling term with the v₅ = 1 fundamental level, providing standard deviation of 40.2 kHz.

At the same time, the description of the v₅ = 1 vibration (E symmetry, 776 cm⁻¹), studied previously with high-resolution as an isolated level, was also improved. The quantitative interpretation of the newly assigned 612 MMW data and the significantly extended set of IR assignments necessitated the introduction of the second-order Coriolis interaction with v₃ = 2, but more importantly of an anharmonic interaction with the v₆ = 3 (A₁ + A₂ + E, near 782 cm⁻¹) level. For this latter level more than 200 rotational transitions, together with several series of rovibrational transitions, could finally be assigned and included in the fit.

我们最近分析了氯仿 CH ³⁵ Cl ₃在 v ₃  = v ₆  = 1 (E 对称性) 和 v ₆  = 2 (A ₁  +  E ) 激发振动态下的宽带毫米波旋转光谱。在目前的工作中，我们使用相同的光谱（记录在 150 - 330 和 360-660 GHz 光谱区域）对同一分子的 v ₂  = 1 和 v ₃  = 2 A ₁状态进行旋转分析，一起对 v ₅ =1 (E) 基本振动进行了新的分析。

对于 v ₂  = 1 状态（A _1，接近 677 cm ^-1），指定数据的主体包括 392 个旋转转换。相应的频率拟合在一个孤立级模型中，标准偏差为 36.4 kHz，获得的参数与之前的 IR 工作非常吻合。

对于 v ₃  = 2 振动状态（A ₁，接近 734 cm ^-1），总共分配了 351 个旋转转变。通过包含具有 v ₅  = 1 基本电平的二阶科里奥利耦合项来改进它们的拟合，提供 40.2 kHz 的标准偏差。

同时，先前以高分辨率作为孤立水平研究的 v ₅  = 1 振动（E 对称性，776 cm ^-1）的描述也得到了改进。新分配的 612 MMW 数据的定量解释和显着扩展的 IR 分配集需要引入与 v ₃  = 2的二阶科里奥利相互作用，但更重要的是引入与 v ₆  = 3的非谐波相互作用（A ₁  + A ₂  + E，接近 782 cm ^-1 ) 水平。对于后一个级别，超过 200 个旋转过渡，以及几个系列的振动过渡，最终可以分配并包含在拟合中。