Abstract The infrared spectrum of ethylene-d3 (12C2HD3) was measured between 830 and 1110 c m - 1 , covering the ν3, ν6 and ν8 bands, using a Fourier transform infrared (FTIR) spectrometer at an unapodized resolution of 0.0019 cm−1. The three upper vibrational states were found to mutually-interact through Coriolis and anharmonic resonances. A total of 2128 a- and b-type absorption lines of the ν3 band and 3107c-type lines of the ν8 band were assigned in this work. Although the ν6 band is relatively weak, 246 spectral lines were identified and included in the final fit for the rovibrational parameters of the upper vibrational states. Using a Hermitian Hamiltonian comprising Watson's-type rotational operators and off-diagonal interaction terms, three sets of rovibrational constants up to quartic terms were derived for the v3 = 1, v6 = 1 and v8 = 1 states together with thirteen interaction parameters, with a root-mean-square (rms) deviation of the fit = 0.00059 cm−1. The band centres of the ν3, ν6 and ν8 bands were determined to be 1044.260675 ± 0.000025 cm−1, 998.60182 ± 0.00060 cm−1 and 918.732573 ± 0.000019 cm−1 respectively. A set of ground state rovibrational constants of 12C2HD3 up to five quartic constants was also derived with improved precision from a simultaneous fit of 782 ground state combination differences (GSCDs) from a-type infrared transitions of the ν3 band and 1422 GSCDs from the c-type ν8 band from the present analysis, together with 377 GSCDs from the previous work on the 2ν8 band. The rms deviation of the GSCD fit was 0.00039 c m - 1 . The experimental spectroscopic parameters compare favourably with the quantum-chemically calculated values at the MP2/cc-pVQZ and B3LYP/cc-pVQZ levels of theory.

中文翻译：

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830 - 1110 cm-1 区域内 12C2HD3 的高分辨率 FTIR 光谱：研究 v3 = 1、v6 = 1 和 v8 = 1 三元组内的科里奥利和非谐相互作用

摘要 乙烯-d3 (12C2HD3) 的红外光谱在 830 和 1110 cm - 1 之间测量，覆盖 ν3、ν6 和 ν8 波段，使用傅里叶变换红外 (FTIR) 光谱仪以 0.0019 cm-1 的非变迹分辨率测量。发现三个上层振动状态通过科里奥利共振和非谐共振相互作用。在这项工作中总共分配了 2128 条 ν3 波段的 a 和 b 型吸收线和 ν8 波段的 3107c 型吸收线。尽管 ν6 波段相对较弱，但确定了 246 条谱线并将其包含在上振动态的振动参数的最终拟合中。使用包含沃森型旋转算子和非对角相互作用项的厄米哈密顿量，推导出了 v3 = 1 的三组直至四次项的振动常数，v6 = 1 和 v8 = 1 状态以及十三个交互参数，拟合的均方根 (rms) 偏差 = 0.00059 cm−1。ν3、ν6 和 ν8 波段的波段中心分别确定为 1044.260675 ± 0.000025 cm-1、998.60182 ± 0.00060 cm-1 和 918.732573 ± 0.000019 cm-1。通过同时拟合 ν3 波段的 a 型红外跃迁的 782 个基态组合差异 (GSCD) 和来自 c-的 1422 个 GSCD，还得到了一组高达五个四次常数的 12C2HD3 基态振动常数。来自当前分析的 ν8 型带，以及来自先前关于 2ν8 带的工作的 377 个 GSCD。GSCD 拟合的均方根偏差为 0.00039 cm-1。