Gas-liquid interface influencing electronic structure of phenol based on molecular dynamics simulations and theoretical X-ray absorption spectroscopy

The study of atomic-scale molecular properties is vital for understanding mass transfer mechanisms and chemical reactions at the gas-liquid interface of plasma in contact with liquid. In this study, we conducted molecular dynamics simulations based on density functional theory to investigate the influences of the gas-liquid interface on the electronic structure of phenol. The probability distribution of the polar angles of phenol at the gas-liquid interface indicated that the -OH group preferred to remain in the liquid phase, contrary to the aromatic ring that preferred to remain in the gaseous phase. The geometric configurations at various polar angles were extracted based on the probability distribution to evaluate the inner-shell X-ray absorption spectra (XAS) of phenol. Moreover, the chemical shifts of all carbon and oxygen atoms were obtained for the atomic-selected merit of XAS. As compared to the gaseous phase, the first transition energies from the O(1s) transition of phenol at the gas-liquid interface decreased by approximately 0.6380 +/- 0.3273 eV. Furthermore, the gas-liquid interface disassociated the plane symmetric Cs group and significantly altered the oscillator strengths, thus converting forbidden transition to allowed transition. The data obtained in this study provide insightful guidance for interpreting the experimental XAS and influences of the gas-liquid interface on the molecular electronic structure of phenol. (C) 2021 Elsevier B.V. All rights reserved.