Vibrational spectroscopy of neutral and cationic 2-Methoxyethanol

Zhou，Xiaohu1; Huang，Ende1,2; Zhong，Licheng1; Liu，Siyue1,3; Ma，Shuze1,2; Li，Hongwei1; Yang，Xueming1,4,5; Dong，Wenrui1,5

2023-12-15

10.1016/j.molstruc.2023.136389

Journal of Molecular Structure   Impact Factor & Quartile

0022-2860

Hydrogen bonding interactions, such as the O-H···O interaction, play a crucial role in stabilizing conformations of both organic and biological molecules. In this study, we employed the infrared (IR)–vacuum-ultraviolet (VUV) non-resonant ionization detected IR spectroscopy (NRID-IR) method to investigate the molecular structure of neutral and cationic 2-methoxyethanol (CHOCHCHOH, 2-ME). The stable structures and anharmonic IR spectra of neutral and cationic 2-ME were calculated using density functional theory (DFT) at the B3LYP-D3(BJ)/def2-TZVPP level. Our results revealed that the two most stable conformers of neutral 2-ME exhibit a weak O-H···O intramolecular hydrogen bond, while the cationic 2-ME lacks the O-H···O interaction but contains a C-H···O intramolecular hydrogen bond. A comparison of the experimental and theoretical IR absorption spectra reveals that the most stable conformer (gauche-(anti-gauche)-trans) is the primary contributor to the observed IR spectra of neutral 2-ME in the 2700–7250 cm range. Similarly, the second stable conformer is found to be the dominant contributor to the observed IR spectra of cationic 2-ME in the range of 2700–7100 cm. Additionally, the C-H fundamental stretching mode of cationic 2-ME is found to be blue-shifted by approximately 100 cm compared to that of neutral 2-ME. Furthermore, the natural bond orbital (NBO) analysis suggests that in neutral 2-ME, the n(O)→σ*(CH) interactions result in significant negative hyperconjugation, leading to the weakening of CH bonds and a subsequent reduction in vibrational energy.

Gas phase infrared spectroscopy Intramolecular hydrogen bond Molecular structure NBO analysis Negative hyperconjugation

SCI

English

Others

Chinese Academy of Sciences[GJJSTD20220001];

WOS:001097763100001

CHEMISTRY

2-s2.0-85167606841

Scopus

1.State Key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian,116023,China
2.University of Chinese Academy of Sciences,Beijing,100049,China
3.Key Laboratory of Materials Modification by Laser,Ion,and Electron Beams,Chinese Ministry of Education,School of Physics,Dalian University of Technology,Dalian,116024,China
4.Department of Chemistry,Southern University of Science and Technology,Shenzhen,518055,China
5.Hefei National Laboratory,Hefei,230088,China

Zhou，Xiaohu,Huang，Ende,Zhong，Licheng,et al. Vibrational spectroscopy of neutral and cationic 2-Methoxyethanol[J]. Journal of Molecular Structure,2023,1294.

Zhou，Xiaohu.,Huang，Ende.,Zhong，Licheng.,Liu，Siyue.,Ma，Shuze.,...&Dong，Wenrui.(2023).Vibrational spectroscopy of neutral and cationic 2-Methoxyethanol.Journal of Molecular Structure,1294.

Zhou，Xiaohu,et al."Vibrational spectroscopy of neutral and cationic 2-Methoxyethanol".Journal of Molecular Structure 1294(2023).