The University of Southampton
University of Southampton Institutional Repository

A spectroscopic study of the reaction between Br2 and dimethyl sulphide, and comparison with a parallel study made on Cl2+DMS

A spectroscopic study of the reaction between Br2 and dimethyl sulphide, and comparison with a parallel study made on Cl2+DMS
A spectroscopic study of the reaction between Br2 and dimethyl sulphide, and comparison with a parallel study made on Cl2+DMS
The reaction between molecular bromine and dimethyl sulfide (DMS) has been studied both as a co-condensation reaction in low temperature matrices by infrared (IR) matrix isolation spectroscopy and in the gas-phase at low pressures by UV photoelectron spectroscopy (PES). The co-condensation reaction leads to the formation of the molecular van der Waals adduct DMS–Br2. This was identified by IR spectroscopy supported by results of electronic structure calculations. Calculation of the minimum energy structures in important regions of the reaction surface and computed IR spectra of these structures, which could be compared with the experimental spectra, allowed the structure of the adduct (Cs) to be determined. The low pressure (ca. 10-5 mbar) gas-phase reaction was studied by UV-PES, but did not yield any observable products, indicating that a third body is necessary for the adduct to be stabilised. These results are compared with parallel co-condensation and gas-phase reactions between DMS and Cl2. For this reaction, a similar van der Waals adduct DMS–Cl2 is observed by IR spectroscopy in the co-condensation reactions, but in the gas-phase, this adduct converts to a covalently bound structure Me2SCl2, observed in PES studies, which ultimately decomposes to monochlorodimethylsulfide and HCl. For these DMS + X2 reactions, computed relative energies of minima and transition states on the potential energy surfaces are presented which provide an interpretation for the products observed from the two reactions studied. The implications of the results obtained to atmospheric chemistry are discussed.
1463-9076
2075-2082
Beccaceci, Sonya
379c1164-a987-4fc7-94ff-12646acdb02e
Ogden, J. Steven
5a99fd42-75e7-4f7b-a347-ac2b1717b8b3
Dyke, John M.
46393b45-6694-46f3-af20-d7369d26199f
Beccaceci, Sonya
379c1164-a987-4fc7-94ff-12646acdb02e
Ogden, J. Steven
5a99fd42-75e7-4f7b-a347-ac2b1717b8b3
Dyke, John M.
46393b45-6694-46f3-af20-d7369d26199f

Beccaceci, Sonya, Ogden, J. Steven and Dyke, John M. (2010) A spectroscopic study of the reaction between Br2 and dimethyl sulphide, and comparison with a parallel study made on Cl2+DMS. Physical Chemistry Chemical Physics, 12, 2075-2082. (doi:10.1039/b917173h).

Record type: Article

Abstract

The reaction between molecular bromine and dimethyl sulfide (DMS) has been studied both as a co-condensation reaction in low temperature matrices by infrared (IR) matrix isolation spectroscopy and in the gas-phase at low pressures by UV photoelectron spectroscopy (PES). The co-condensation reaction leads to the formation of the molecular van der Waals adduct DMS–Br2. This was identified by IR spectroscopy supported by results of electronic structure calculations. Calculation of the minimum energy structures in important regions of the reaction surface and computed IR spectra of these structures, which could be compared with the experimental spectra, allowed the structure of the adduct (Cs) to be determined. The low pressure (ca. 10-5 mbar) gas-phase reaction was studied by UV-PES, but did not yield any observable products, indicating that a third body is necessary for the adduct to be stabilised. These results are compared with parallel co-condensation and gas-phase reactions between DMS and Cl2. For this reaction, a similar van der Waals adduct DMS–Cl2 is observed by IR spectroscopy in the co-condensation reactions, but in the gas-phase, this adduct converts to a covalently bound structure Me2SCl2, observed in PES studies, which ultimately decomposes to monochlorodimethylsulfide and HCl. For these DMS + X2 reactions, computed relative energies of minima and transition states on the potential energy surfaces are presented which provide an interpretation for the products observed from the two reactions studied. The implications of the results obtained to atmospheric chemistry are discussed.

Text
Br2+_DMS_FINALfinal.doc - Other
Download (2MB)

More information

Published date: March 2010
Organisations: Chemistry

Identifiers

Local EPrints ID: 147165
URI: https://eprints.soton.ac.uk/id/eprint/147165
ISSN: 1463-9076
PURE UUID: 555bdd05-11f8-4055-8962-93d5adcdf286
ORCID for John M. Dyke: ORCID iD orcid.org/0000-0002-9808-303X

Catalogue record

Date deposited: 23 Apr 2010 10:58
Last modified: 20 Jul 2019 01:27

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×