A TPD and RAIRS comparison of the low temperature behavior of benzene, toluene, and xylene on graphite

Salter, Tara L, Stubbing, James W, Brigham, Lorna and Brown, Wendy A (2018) A TPD and RAIRS comparison of the low temperature behavior of benzene, toluene, and xylene on graphite. The Journal of Chemical Physics, 149 (164705). pp. 1-11. ISSN 0021-9606

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Abstract

The first comparative study of the surface behavior of four small aromatic molecules, benzene, toluene, p-xylene, and o-xylene, adsorbed on graphite at temperatures ≤30 K, is presented. Intermolecular interactions are shown to be important in determining the growth of the molecules on the graphite surface at low (monolayer) exposures. Repulsive intermolecular interactions dominate the behavior of benzene and toluene. By contrast, stronger interactions with the graphite surface are observed for the xylene isomers, with islanding observed for o-xylene. Multilayer desorption temperatures and energies increase with the size of the molecule, ranging from 45.5 to 59.5 kJ mol−1 for benzene and p-xylene, respectively. Reflection absorption infrared spectroscopy gives insight into the effects of thermal processing on the ordering of the molecules. Multilayer benzene, p-xylene, and o-xylene form crystalline structures following annealing of the ice. However, we do not observe an ordered structure for toluene in this study. The ordering of p-xylene shows a complex relationship dependent on both the annealing temperature and exposure.

Item Type: Article
Schools and Departments: School of Life Sciences > Chemistry
Subjects: Q Science > QD Chemistry
Q Science > QD Chemistry > QD0450 Physical and theoretical chemistry
Depositing User: Wendy Brown
Date Deposited: 18 Oct 2018 16:22
Last Modified: 24 Jan 2019 17:06
URI: http://sro.sussex.ac.uk/id/eprint/79577

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Project NameSussex Project NumberFunderFunder Ref
Evolution of ices: From molecular cloud to oceanG1613STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCILST/M000869/1