Abstract Perdeutero-spiropentane (C5D8) has been synthesized and infrared spectra were taken from 400 to 4000 cm−1 at low sample pressures in a 22 m multipass cell. The spectral resolution (0.0015 cm−1) reveals thousands of individual rovibrational transitions for several fundamental bands occurring in the spectral region of 500–1100 cm−1. C5D8 ground state constants reported in a previous study of the ν15 parallel band at 1054 cm−1 [1] were improved significantly in the present work by adding combination-differences derived from ν16 parallel and ν24 perpendicular band analyses. The larger data set at higher J values also allowed determination of the ground state K″ = 2 splitting constant (Δ2″ = 0.76(2) × 10−9 cm−1). For ν16, the band origin is 847.16933(5) cm−1 and changes in upper state rotational constants are ΔA = –0.0013411(5) and ΔB = –0.0002021(1) (in units of cm−1). Overlapping, and in Fermi resonance with ν16, is a second parallel band which, from Gaussian calculations at the anharmonic level, is assigned as the b2 combination ν8 + ν12, with band origin of 840.5434(1) and ΔA = –0.0003500(7) and ΔB = –0.0003502(1) cm−1. For ν24 analogous values are 556.41453(2) and ΔA = –0.00032295(9) and ΔB = –0.00016782(4) cm−1. The analyses also yield accurate values for the changes in both quartic and sextic centrifugal distortion constants and, for ν24, values for the l-doubling constants q+ and q−. Theoretical calculations of the rovibrational parameters aided in the analysis and the numerical values are in good agreement with experimental results.

中文翻译：

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全氘-螺戊烷、C5D8 的几个高分辨率红外波段的分析

摘要 Perdeutero-spiropentane (C5D8) 已被合成，并在 22 m 多通道池中在低样品压力下从 400 到 4000 cm-1 获取红外光谱。光谱分辨率 (0.0015 cm-1) 揭示了发生在 500-1100 cm-1 光谱区域内的几个基本波段的数千个单独的振动跃迁。通过添加从 ν16 平行和 ν24 垂直带分析得出的组合差异，C5D8 基态常数在先前对 1054 cm-1 [1] 处的 ν15 平行带的研究中得到了显着改善。较高 J 值下的较大数据集也允许确定基态 K″ = 2 分裂常数 (Δ2″ = 0.76(2) × 10−9 cm−1)。对于 ν16，能带原点为 847.16933(5) cm-1，上态旋转常数的变化为 ΔA = –0.0013411(5) 和 ΔB = –0。0002021(1)（以 cm−1 为单位）。与 ν16 重叠并与 ν16 发生费米共振的是第二个平行带，根据非谐能级的高斯计算，该带被指定为 b2 组合 ν8 + ν12，带原点为 840.5434(1) 和 ΔA = –0.0003500(7)并且 ΔB = –0.0003502(1) cm-1。对于 ν24 类似值是 556.41453(2) 和 ΔA = –0.00032295(9) 和 ΔB = –0.00016782(4) cm-1。分析还得出四次和六次离心畸变常数变化的准确值，以及对于 ν24 的 l 倍增常数 q+ 和 q− 的值。振动参数的理论计算有助于分析，数值与实验结果吻合良好。来自非谐波水平的高斯计算，被指定为 b2 组合 ν8 + ν12，带原点为 840.5434(1) 和 ΔA = –0.0003500(7) 和 ΔB = –0.0003502(1) cm-1。对于 ν24 类似值是 556.41453(2) 和 ΔA = –0.00032295(9) 和 ΔB = –0.00016782(4) cm-1。分析还得出四次和六次离心畸变常数变化的准确值，以及对于 ν24 的 l 倍增常数 q+ 和 q− 的值。振动参数的理论计算有助于分析，数值与实验结果吻合良好。来自非谐波水平的高斯计算，被指定为 b2 组合 ν8 + ν12，带原点为 840.5434(1) 和 ΔA = –0.0003500(7) 和 ΔB = –0.0003502(1) cm-1。对于 ν24 类似值是 556.41453(2) 和 ΔA = –0.00032295(9) 和 ΔB = –0.00016782(4) cm-1。分析还得出四次和六次离心畸变常数变化的准确值，以及对于 ν24 的 l 倍增常数 q+ 和 q− 的值。振动参数的理论计算有助于分析，数值与实验结果吻合良好。分析还得出四次和六次离心畸变常数变化的准确值，以及对于 ν24 的 l 倍增常数 q+ 和 q− 的值。振动参数的理论计算有助于分析，数值与实验结果吻合良好。分析还得出四次和六次离心畸变常数变化的准确值，以及对于 ν24 的 l 倍增常数 q+ 和 q− 的值。振动参数的理论计算有助于分析，数值与实验结果吻合良好。