Nejad Arman, Meyer Enno, Suhm Martin A
Institute of Physical Chemistry, University of Göttingen, Tammannstr. 6, 37077 Göttingen, Germany.
J Phys Chem Lett. 2020 Jul 2;11(13):5228-5233. doi: 10.1021/acs.jpclett.0c01462. Epub 2020 Jun 18.
Three energetically close pairs of vibrational states in glycolic acid are investigated by Raman spectroscopy in a supersonic jet to provide challenging benchmarks for vibrational and electronic structure theory and to solve some open issues in this prototypical hydroxy acid. The alcoholic OH stretching fundamental is located only 8 cm below the acidic OH stretch at 3586 cm, much less shifted than predicted by previous anharmonic calculations and by experimental analogy to a fluorene derivative. This and further near-degeneracies in the CH and C=O stretching region are used to assess the predictive power of an exploratory set of quantum chemical calculations including anharmonic VPT2 corrections.
通过在超声速射流中利用拉曼光谱研究乙醇酸中三对能量相近的振动状态，为振动和电子结构理论提供具有挑战性的基准，并解决这种典型羟基酸中的一些未解决问题。醇式OH伸缩基频位于3586 cm处酸性OH伸缩频率下方仅8 cm处，其位移比先前的非谐计算以及与芴衍生物的实验类比所预测的要小得多。CH和C=O伸缩区域中的这一情况以及进一步的近简并性被用于评估一组包括非谐VPT2校正的探索性量子化学计算的预测能力。
