Experimental and Modeling Studies of Local and Nanoscale para-Cresol Behavior: A Comparison of Classical Force Fields

Katie S.C. Morton, Alin M. Elena, Jeff Armstrong, Alexander J. O’Malley

Research output: Contribution to journalArticlepeer-review

Abstract

The dynamics of bulk liquid para-cresol from 340-390 K was probed using a tandem quasielastic neutron scattering (QENS) and molecular dynamics (MD) approach, due to its relevance as a simple model component of lignin pyrolysis oil. QENS experiments observed both translational jump diffusion and isotropic rotation, with diffusion coefficients ranging from 10.1 to 28.6 × 10-10 m2s-1 and rotational rates from 5.7 to 9.2 × 1010 s-1. The associated activation energies were 22.7 ± 0.6 and 10.1 ± 1.2 kJmol-1 for the two different dynamics. MD simulations applying two different force field models (OPLS3 and OPLS2005) gave values close to the experimental diffusion coefficients and rotational rates obtained upon calculating the incoherent dynamic structure factor from the simulations over the same time scale probed by the QENS spectrometer. The simulations gave resulting jump diffusion coefficients that were slower by factors of 2.0 and 3.8 and rates of rotation that were slower by factors of 1.2 and 1.6. Comparing the two force field sets, the OPLS3 model showed slower rates of dynamics likely due to a higher molecular polarity, leading to greater quantities and strengths of hydrogen bonding.

Original languageEnglish
Pages (from-to)3305-3316
JournalJournal of Physical Chemistry A
Volume127
Issue number15
Early online date11 Apr 2023
DOIs
Publication statusPublished - 20 Apr 2023

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'Experimental and Modeling Studies of Local and Nanoscale para-Cresol Behavior: A Comparison of Classical Force Fields'. Together they form a unique fingerprint.

Cite this