Huang Qian-Rui, Yano Kazuyoshi, Yang Yaodi, Fujii Asuka, Kuo Jer-Lai
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan.
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan.
Phys Chem Chem Phys. 2024 Apr 3;26(14):10757-10768. doi: 10.1039/d4cp00458b.
Near-infrared (NIR) spectra of HO⋯X (X = Ar, N, and CO, = 1-3) in the first overtone region of OH-stretching vibrations (4800-7000 cm) were measured. Not only OH-stretching overtones but also several combination bands are major features in this region, and assignments of these observed bands are not obvious at a glance. High-precision anharmonic vibrational simulations based on the discrete variable representation approach were performed. The simulated spectra show good agreement with the observed ones and provide firm assignments of the observed bands, except in the case of X = CO, in which higher order vibrational mode couplings seem significant. This agreement demonstrates that the present system can be a benchmark for high precision anharmonic vibrational computations of NIR spectra. Band broadening in the observed spectra becomes remarkable with an increase of the interaction with the solvent molecule (X). The origin of the band broadening is explored by rare gas tagging experiments and anharmonic vibrational simulations of hot bands.
测量了OH伸缩振动（4800 - 7000 cm）第一泛音区域中HO⋯X（X = Ar、N和CO， = 1 - 3）的近红外（NIR）光谱。在该区域中，不仅OH伸缩泛音，而且几个组合带都是主要特征，这些观察到的谱带的归属并非一目了然。基于离散变量表示法进行了高精度非谐振动模拟。模拟光谱与观察到的光谱显示出良好的一致性，并为观察到的谱带提供了可靠的归属，除了X = CO的情况，在这种情况下高阶振动模式耦合似乎很显著。这种一致性表明，本系统可以作为NIR光谱高精度非谐振动计算的基准。随着与溶剂分子（X）相互作用的增加，观察到的光谱中的谱带展宽变得显著。通过稀有气体标记实验和热带的非谐振动模拟来探索谱带展宽的起源。
