The overtone v₆ = 2 (~520 cm⁻¹) and combination v₃ = v₆ = 1 (~627 cm⁻¹) vibrational levels of chloroform CH³⁵Cl₃ have been studied by millimeter wave spectroscopy, in the regions 150-330 and 360-660 GHz, corresponding to J = 22-49 and 55-99. Like the v₆ = 1 fundamental vibration, the v₃ = v₆ = 1 combination level has an accidentally small value of C-B-Cζ ~ −0.0029 cm⁻¹. Hence, a global q₂₂ resonance (Δk = Δl = ±2) connects the (k-1, l₆ = -1) and (k+1, l₆ = +1) sublevels. As a consequence, several resonant q₁₂ (Δk = ±1, Δl = ∓2) crossings occur, which enabled the precise determination of the q₁₂ interaction parameter for this state. Altogether, 1182 rotational transitions in the v₃ = v₆ = 1 combination level have been measured and fitted, with a standard deviation of 41.2 kHz. For the v₆ = 2 (A₁+E) overtone level, the combined effects of the q₂₂ and q₁₂ l-type interactions induce resonant crossings between the (k, l₆ = 0)/(k+1, l₆ = -2) pairs of levels, for a large variety of k values. Altogether, 1463 rotational transitions in the (l₆ = 0) A₁ sublevel and 2924 rotational transitions in the (l₆ = ±2) E sublevels, together with nine perturbation-allowed transitions induced by the q₁₂ (Δk = ±1, Δl = ∓2) interaction, have been measured and fitted, with a global standard deviation of 41.4 kHz. This resulted in the first accurate determination of the molecular constants of this overtone level.

已通过毫米波光谱法在区域150-150中研究了氯仿CH ³⁵ Cl ₃的泛音v ₆  = 2（〜520 cm ^-1）和组合v ₃  = v ₆  = 1（〜627 cm ^-1）的振动水平。330和360-660 GHz，对应于J  = 22-49和55-99。像在V ₆  = 1基本振动中，V ₃  = V ₆  = 1组合电平具有的意外小的值Ç -乙- Cζ〜-0.0029厘米^-1。因此，整体q ₂₂共振（Δķ  =Δ升 =±2）将所述（ķ -1，升₆  = -1）和（ķ 1，升₆  = 1）能级。因此，几个谐振q ₁₂（Δ ķ  =±1，Δ升 =∓2）发生交叉，这使精确确定q ₁₂为这种状态下相互作用参数。总共 测量并拟合了v ₃  = v ₆ = 1组合级别中的1182个旋转过渡，标准偏差为41.2 kHz。对于v ₆  = 2（A ₁+ E）泛音水平，q ₂₂和q ₁₂ l型相互作用的组合效应在（k，l ₆  = 0）/（k +1，l ₆  = -2）水平对之间引起共振交叉，对于各种各样的k值。在（l ₆  = 0）A ₁子级中总共有1463个旋转跃迁，在（l ₆  =±2）E子级中共2924个旋转跃迁，以及q ₁₂引起的9个扰动允许跃迁（Δk  =±1 ，Δ升 =∓2）相互作用，已经过测量和拟合，全局标准偏差为41.4 kHz。这导致该泛音水平的分子常数的首次精确测定。