Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland.
J Phys Chem A. 2009 Mar 12;113(10):2218-31. doi: 10.1021/jp809839t.
We report the infrared spectrum of CH(2)D(2) measured in the range from 2800 to 6600 cm(-1) with the Zurich high-resolution Fourier transform interferometer Bruker IFS 125 prototype (ZP 2001, with instrumental bandwidth less than 10(-3) cm(-1)) at 78 K in a collisional enclosive flow cooling cell used in the static mode. Precise experimental values (with uncertainties between 0.0001 and 0.001 cm(-1)) were obtained for the band centers by specific assignment of transitions to the J = 0 level of 71 vibrational levels. In combination with 22 previously known band centers, these new results were used as the initial information for the determination of the harmonic frequencies, force constant parameters F(ij), anharmonic coefficients, and vibrational resonance interaction parameters. A set of 47 fitted parameters for an effective Hamiltonian reproduces the vibrational level structure of the CH(2)D(2) molecule up to 6600 cm(-1) with a root-mean-square deviation d(rms) = 0.67 cm(-1). The results are discussed in relation to the multidimensional potential hypersurface of methane and its vibrational dynamics.
我们报告了在 78 K 下使用静态模式中的碰撞封闭流动冷却池，用苏黎世高分辨率傅里叶变换干涉仪 Bruker IFS 125 原型（ZP 2001，仪器带宽小于 10^-3 cm^-1）在 2800 到 6600 cm^-1 范围内测量的 CH(2)D(2)的红外光谱。通过将跃迁特定分配给 71 个振动能级的 J = 0 能级，获得了具有 0.0001 到 0.001 cm^-1 之间不确定性的带中心的精确实验值。结合 22 个先前已知的带中心，这些新结果被用作确定谐波频率、力常数参数 F(ij)、非谐系数和振动共振相互作用参数的初始信息。一套适用于有效哈密顿量的 47 个拟合参数，以 0.67 cm^-1 的均方根偏差 d(rms)，在 6600 cm^-1 以内再现了 CH(2)D(2)分子的振动能级结构。结果与甲烷的多维势能面及其振动动力学有关进行了讨论。
