Dynamic Signature of Molecular Association in Methanol

Published

July 7, 2016

Author(s)

Christopher E. Bertrand, Jeffrey L. Self, John R. Copley, Antonio Faraone

Abstract

Quasielastic neutron scattering measurements and molecular dynamics simulations were combined to investigate the collective dynamics of deuterated methanol. A slow, non-Fickian mode was observed in addition to the standard heat mode. The qualitative behavior of this mode is similar to the previously observed α-relaxation in supercooled water [M.C. Bellissent-Funel et al,. Phys. Rev. Lett. 85, 3644 (2000)] and also originates from the formation and dissolution of hydrogen-bonded associates (supermolecular clusters). In methanol, however, this mode is distinguishable well above the freezing transition. This finding raises the possibility that an emergent slow mode is not unique to supercooled water, but may instead be a general feature of hydrogen-bonding liquids.

Citation

Journal of Chemical Physics

Volume

145

Issue

1

Pub Type

Journals

Download Paper

Local Download

Keywords

Associates, H-bond, QENS, MD

Citation

Bertrand, C. , Self, J. , Copley, J. and Faraone, A. (2016), Dynamic Signature of Molecular Association in Methanol, Journal of Chemical Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=919680 (Accessed December 21, 2024)