The Influence of Chain Dynamics on the Far Infrared Spectrum of Liquid Methanol-Water Mixtures

doi:https://doi.org/10.2172/878842

Title: The Influence of Chain Dynamics on the Far Infrared Spectrum of Liquid Methanol-Water Mixtures

Full Record
Other Related Research

Abstract

Far-infrared absorption spectroscopy has been used to study the low frequency ({center_dot} 100 cm{sup -1}) intermolecular modes of methanol in mixtures with water. With the aid of a first principles molecular dynamics simulation on an equivalent system, a detailed understanding about the origin of the low frequency IR modes has been established. The total dipole spectrum from the simulation suggests that the bands appearing in the experimental spectra at approximately 55 cm{sup -1} and 70 cm{sup -1} in methanol and methanol-rich mixtures arise from both fluctuations and torsional motions occurring within the methanol hydrogen-bonded chains. The influence of these modes on both the solvation dynamics and the relaxation mechanisms in the liquid are discussed within the context of recent experimental and theoretical results that have emerged from studies focusing on the short time dynamics in the methanol hydrogen bond network.

Authors:: Woods, K N; Wiedemann, H

Publication Date:: 2005-07-12

Research Org.:: Stanford Linear Accelerator Center (SLAC)

Sponsoring Org.:: USDOE

OSTI Identifier:: 878842

Report Number(s):: SLAC-PUB-11339
TRN: US200612%%177

DOE Contract Number:: AC02-76SF00515

Resource Type:: Technical Report

Country of Publication:: United States

Language:: English

Subject:: 08 HYDROGEN; 10 SYNTHETIC FUELS; ABSORPTION SPECTROSCOPY; CHAINS; DIPOLES; FLUCTUATIONS; FOCUSING; HYDROGEN; METHANOL; MIXTURES; ORIGIN; RELAXATION; SIMULATION; SOLVATION; SPECTRA; WATER; Other,ACCPHY, BIO, CHEM, MATSCI

Citation Formats


                    Woods, K N, /Stanford U., Phys. Dept., Wiedemann, H, and /SLAC, SSRL. The Influence of Chain Dynamics on the Far Infrared Spectrum of Liquid Methanol-Water Mixtures.  United States: N. p., 2005. 
        Web.  doi:10.2172/878842.

Copy to clipboard


                    Woods, K N, /Stanford U., Phys. Dept., Wiedemann, H, & /SLAC, SSRL. The Influence of Chain Dynamics on the Far Infrared Spectrum of Liquid Methanol-Water Mixtures.  United States.  https://doi.org/10.2172/878842

Copy to clipboard


                    Woods, K N, /Stanford U., Phys. Dept., Wiedemann, H, and /SLAC, SSRL. Tue .  
        "The Influence of Chain Dynamics on the Far Infrared Spectrum of Liquid Methanol-Water Mixtures".  United States.  https://doi.org/10.2172/878842.  https://www.osti.gov/servlets/purl/878842.

Copy to clipboard


                    
@article{osti_878842,

  title        = {The Influence of Chain Dynamics on the Far Infrared Spectrum of Liquid Methanol-Water Mixtures},

  author       = {Woods, K N and /Stanford U., Phys. Dept. and Wiedemann, H and /SLAC, SSRL},

  abstractNote = {Far-infrared absorption spectroscopy has been used to study the low frequency ({center_dot} 100 cm{sup -1}) intermolecular modes of methanol in mixtures with water. With the aid of a first principles molecular dynamics simulation on an equivalent system, a detailed understanding about the origin of the low frequency IR modes has been established. The total dipole spectrum from the simulation suggests that the bands appearing in the experimental spectra at approximately 55 cm{sup -1} and 70 cm{sup -1} in methanol and methanol-rich mixtures arise from both fluctuations and torsional motions occurring within the methanol hydrogen-bonded chains. The influence of these modes on both the solvation dynamics and the relaxation mechanisms in the liquid are discussed within the context of recent experimental and theoretical results that have emerged from studies focusing on the short time dynamics in the methanol hydrogen bond network.},

  doi          = {10.2172/878842},

  url          = {https://www.osti.gov/biblio/878842},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {2005},

  month        = {7}

}

Copy to clipboard

Technical Report:

View Technical Report

https://doi.org/10.2172/878842

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

The Influence of Chain Dynamics on theFar-Infrared Spectrum of Liquid Methanol

Technical Report Woods, K N ; /Stanford U., Phys. Dept. ; Wiedemann, H ; ...

Far-infrared absorption spectroscopy is used to investigate the low frequency ({center_dot} 100 cm{sup -1}) intermolecular interactions in liquid methanol. Using an intense source of far-infrared radiation, modes are elucidated at approximately 30 cm{sup -1} and 70 cm{sup -1} in the absorption spectrum. These modes are believed to arise from intermolecular bending and librational motions respectively and are successfully reproduced in an ab initio molecular dynamics simulation of methanol.
https://doi.org/10.2172/878852

Full Text Available
The effect of hydrogen bonding on torsional dynamics: A combined far-infrared jet and matrix isolation study of methanol dimer

Journal Article Kollipost, F. ; Heger, M. ; Suhm, M. A. ; ... - Journal of Chemical Physics

The effect of strong intermolecular hydrogen bonding on torsional degrees of freedom is investigated by far-infrared absorption spectroscopy for different methanol dimer isotopologues isolated in supersonic jet expansions or embedded in inert neon matrices at low temperatures. For the vacuum-isolated and Ne-embedded methanol dimer, the hydrogen bond OH librational mode of the donor subunit is finally observed at ∼560 cm{sup −1}, blue-shifted by more than 300 cm{sup −1} relative to the OH torsional fundamental of the free methanol monomer. The OH torsional mode of the acceptor embedded in neon is observed at ∼286 cm{sup −1}. The experimental findings are heldmore »« less
https://doi.org/10.1063/1.4900922
The solvent dependent shift of the amide I band of a fully solvated peptide in methanol/water mixtures as a local probe for the solvent composition in the peptide/solvent interface

Journal Article Gnanakaran, S - J. Chemistry Physics

We determine the shift and line-shape of the amide I band of a model AK-peptide from molecular dynamics (MD) simulations of the peptide dissolved in methanol/water mixtures with varying composition. The IR-spectra are determined from a transition dipole coupling exciton model. A simplified empirical model Hamiltonian is employed, taking both the effect of hydrogen bonding, as well as intramolecular vibrational coupling into account. We consider a single isolated AK-peptide in a mostly helical conformation, while the solvent is represented by 2600 methanol or water molecules, simulated for a pressure of 1 bar and a temperature of 300 K. Over themore »« less
Full Text Available
Observation of a new vibrational mode of (D{sub 2}O){sub 2} near 68 cm{sup {minus}1} using tunable far-infrared laser spectroscopy

Conference Cruzan, J D ; Loeser, J G ; Bitten, E R

The authors have measured the far-infrared vibration-rotation-tunneling (VRT) spectrum of an intermolecular vibration of (D{sub 2}O){sub 2} near 68 cm{sup -1}. In addition, further transitions of the VRT band of (D{sub 2}O){sub 2} previously reported by Pugliano et al. have been observed. By considering symmetry restraints on the selection rules, these bands have been assigned to the out-of-plane H-bond torsional and in-plane acceptor wagging modes predicted by many theoretical calculations. The experimental-theoretical discrepancy in the measured frequencies of these bands indicates the importance of a fully coupled six-dimensional calculation of the dynamics for the water dimer.
Molecular simulation study of water--methanol mixtures in activated carbon pores

Journal Article Shevade, Abhijit V ; Jiang, Shaoyi ; Gubbins, Keith E - Journal of Chemical Physics

We report a theoretical study of the adsorption behavior of water--methanol mixtures in slit activated carbon micropores. The adsorption isotherms are obtained for a pore of width 2 nm at a temperature of 298 K from grand canonical ensemble Monte Carlo simulations. The water molecules are modeled using the four point transferable intermolecular potential functions (TIP4P) and methanol by the optimized potentials for liquid simulations (OPLS). Carboxyl (COOH) groups are used as active sites on a structured carbon surface. The effect of the relative contributions from dispersion and hydrogen bonding interactions of adsorbates, and of the chemical activation of adsorbentsmore »« less
https://doi.org/10.1063/1.1309012

Similar Records