Molecular dynamics study to identify the reactive sites of a liquid squalane surface

Köhler, SP; Reed, SK; Westacott, RE; Mckendrick, KG

HERO ID

4969214

Reference Type

Journal Article

Year

2006

Language

English

PMID

16800468

HERO ID 4969214
In Press No
Year 2006
Title Molecular dynamics study to identify the reactive sites of a liquid squalane surface
Authors Köhler, SP; Reed, SK; Westacott, RE; Mckendrick, KG
Journal Journal of Physical Chemistry B
Volume 110
Issue 24
Page Numbers 11717-11724
Abstract Molecular dynamics simulations of liquid squalane, C30H62, were performed, focusing in particular on the liquid-vacuum interface. These theoretical studies were aimed at identifying potentially reactive sites on the surface, knowledge of which is important for a number of inelastic and reactive scattering experiments. A united atom force field (Martin, M. G.; Siepmann, J. I. J. Phys. Chem. B 1999, 103, 4508-4517) was used, and the simulations were analyzed with respect to their interfacial properties. A modest but clearly identifiable preference for methyl groups to protrude into the vacuum has been found at lower temperatures. This effect decreases when going to higher temperatures. Additional simulations tracking the flight paths of projectiles directed at a number of randomly chosen surfaces extracted from the molecular dynamics simulations were performed. The geometrical parameters for these calculations were chosen to imitate a typical abstraction reaction, such as the reaction between ground-state oxygen atoms and hydrocarbons. Despite the preference for methyl groups to protrude further into the vacuum, Monte Carlo tracking simulations suggest, on geometric grounds, that primary and secondary hydrogen atoms are roughly equally likely to react with incoming gas-phase atoms. These geometric simulations also indicate that a substantial fraction of the scattered products is likely to undergo at least one secondary collision with hydrocarbon side chains. These results help to interpret the outcome of previous measurements of the internal and external energy distribution of the gas-phase OH products of the interfacial reaction between oxygen atoms and liquid squalane.
Doi 10.1021/jp060431p
Pmid 16800468
Wosid WOS:000238284600018
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English