INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
CH3CH2SCH3 + OH radicals: Temperature dependent rate coefficient and product identification at atmospheric pressure of air
Autor/es:
OKSDATH MANSILLA, G.; PEÑÉÑORY, ALICIA B; ALBU, MIHAELA; BARNES, IAN; WIESEN, PETER; TERUEL, MARIANO A.
Revista:
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY
Editorial:
JOHN WILEY & SONS LTD
Referencias:
Año: 2009
ISSN:
0894-3230
Resumen:
 Relative rate coefficients have been determined for the gas-phase reaction of hydroxyl radicals with ethyl methyl sulfide using isobutene as reference compound. The experiments were performed in a 1080 L quartz glass photoreactor over the temperature range 286-313 K at a total pressure of (760 ± 10) Torr synthetic air using in situ FTIR absorption spectroscopy to monitor the concentration-time behaviors of reactants and products. Hydroxyl radicals (OH) were produced by the 254 nm photolysis of hydrogen peroxide (H2O2).  The kinetic data obtained was used to derive the following Arrhenius expression valid in the temperature range 286-313 K (in units of cm3 molecule-1 s-1): k = (3.0 ±  0.6) x 10-15 exp [(2457 ± 65)/T] The rate coefficient displays a negative temperature dependence and low preexponential factor which supports the existence of an addition mechanism for the reaction involving reversible OH-adduct formation. The results are compared with previous data of other sulfides from the literature and are rationalized in terms of structure-reactivity relationships. Additionally, product identification of the title reaction was performed for the first time by the FTIR technique under atmospheric conditions. Sulfur dioxide, formaldehyde and formic acid were observed as degradation products in agreement with the two possible reaction channels (addition/abstraction).