skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Critical interpretation of CH– and OH– stretching regions for infrared spectra of methanol clusters (CH{sub 3}OH){sub n} (n = 2–5) using self-consistent-charge density functional tight-binding molecular dynamics simulations

Abstract

Vibrational infrared (IR) spectra of gas-phase O–H⋅⋅⋅O methanol clusters up to pentamer are simulated using self-consistent-charge density functional tight-binding method using two distinct methodologies: standard normal mode analysis and Fourier transform of the dipole time-correlation function. The twofold simulations aim at the direct critical assignment of the C–H stretching region of the recently recorded experimental spectra [H.-L. Han, C. Camacho, H. A. Witek, and Y.-P. Lee, J. Chem. Phys. 134, 144309 (2011)]. Both approaches confirm the previous assignment (ibid.) of the C–H stretching bands based on the B3LYP/ANO1 harmonic frequencies, showing that ν{sub 3}, ν{sub 9}, and ν{sub 2} C–H stretching modes of the proton-accepting (PA) and proton-donating (PD) methanol monomers experience only small splittings upon the cluster formation. This finding is in sharp discord with the assignment based on anharmonic B3LYP/VPT2/ANO1 vibrational frequencies (ibid.), suggesting that some procedural faults, likely related to the breakdown of the perturbational vibrational treatment, led the anharmonic calculations astray. The IR spectra based on the Fourier transform of the dipole time-correlation function include new, previously unaccounted for physical factors such as non-zero temperature of the system and large amplitude motions of the clusters. The elevation of temperature results in a considerable non-homogeneous broadening ofmore » the observed IR signals, while the presence of large-amplitude motions (methyl group rotations and PA-PD flipping), somewhat surprisingly, does not introduce any new features in the spectrum.« less

Authors:
 [1];  [2];  [1]
  1. Department of Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
  2. Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan (China)
Publication Date:
OSTI Identifier:
22419859
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 141; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALLOCATIONS; CHARGE DENSITY; CORRELATION FUNCTIONS; DIPOLES; FOURIER TRANSFORMATION; INFRARED SPECTRA; METHANOL; MOLECULAR DYNAMICS METHOD; MONOMERS; NORMAL-MODE ANALYSIS; PROTONS; SIGNALS; SIMULATION

Citation Formats

Nishimura, Yoshifumi, Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan, Lee, Yuan-Pern, Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10617, Taiwan, Irle, Stephan, Institute of Transformative Bio-Molecules, and Witek, Henryk A., E-mail: hwitek@mail.nctu.edu.tw. Critical interpretation of CH– and OH– stretching regions for infrared spectra of methanol clusters (CH{sub 3}OH){sub n} (n = 2–5) using self-consistent-charge density functional tight-binding molecular dynamics simulations. United States: N. p., 2014. Web. doi:10.1063/1.4893952.
Nishimura, Yoshifumi, Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan, Lee, Yuan-Pern, Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10617, Taiwan, Irle, Stephan, Institute of Transformative Bio-Molecules, & Witek, Henryk A., E-mail: hwitek@mail.nctu.edu.tw. Critical interpretation of CH– and OH– stretching regions for infrared spectra of methanol clusters (CH{sub 3}OH){sub n} (n = 2–5) using self-consistent-charge density functional tight-binding molecular dynamics simulations. United States. https://doi.org/10.1063/1.4893952
Nishimura, Yoshifumi, Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan, Lee, Yuan-Pern, Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10617, Taiwan, Irle, Stephan, Institute of Transformative Bio-Molecules, and Witek, Henryk A., E-mail: hwitek@mail.nctu.edu.tw. 2014. "Critical interpretation of CH– and OH– stretching regions for infrared spectra of methanol clusters (CH{sub 3}OH){sub n} (n = 2–5) using self-consistent-charge density functional tight-binding molecular dynamics simulations". United States. https://doi.org/10.1063/1.4893952.
@article{osti_22419859,
title = {Critical interpretation of CH– and OH– stretching regions for infrared spectra of methanol clusters (CH{sub 3}OH){sub n} (n = 2–5) using self-consistent-charge density functional tight-binding molecular dynamics simulations},
author = {Nishimura, Yoshifumi and Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan and Lee, Yuan-Pern and Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10617, Taiwan and Irle, Stephan and Institute of Transformative Bio-Molecules and Witek, Henryk A., E-mail: hwitek@mail.nctu.edu.tw},
abstractNote = {Vibrational infrared (IR) spectra of gas-phase O–H⋅⋅⋅O methanol clusters up to pentamer are simulated using self-consistent-charge density functional tight-binding method using two distinct methodologies: standard normal mode analysis and Fourier transform of the dipole time-correlation function. The twofold simulations aim at the direct critical assignment of the C–H stretching region of the recently recorded experimental spectra [H.-L. Han, C. Camacho, H. A. Witek, and Y.-P. Lee, J. Chem. Phys. 134, 144309 (2011)]. Both approaches confirm the previous assignment (ibid.) of the C–H stretching bands based on the B3LYP/ANO1 harmonic frequencies, showing that ν{sub 3}, ν{sub 9}, and ν{sub 2} C–H stretching modes of the proton-accepting (PA) and proton-donating (PD) methanol monomers experience only small splittings upon the cluster formation. This finding is in sharp discord with the assignment based on anharmonic B3LYP/VPT2/ANO1 vibrational frequencies (ibid.), suggesting that some procedural faults, likely related to the breakdown of the perturbational vibrational treatment, led the anharmonic calculations astray. The IR spectra based on the Fourier transform of the dipole time-correlation function include new, previously unaccounted for physical factors such as non-zero temperature of the system and large amplitude motions of the clusters. The elevation of temperature results in a considerable non-homogeneous broadening of the observed IR signals, while the presence of large-amplitude motions (methyl group rotations and PA-PD flipping), somewhat surprisingly, does not introduce any new features in the spectrum.},
doi = {10.1063/1.4893952},
url = {https://www.osti.gov/biblio/22419859}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 9,
volume = 141,
place = {United States},
year = {Sun Sep 07 00:00:00 EDT 2014},
month = {Sun Sep 07 00:00:00 EDT 2014}
}