INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
Shock Wave Study of the Thermal Dissociations of C3F6 and c-C3F6. I. Dissociation of Hexafluoropropene
Autor/es:
C. J. COBOS; L. SOELTER; E. TELLBACH; J. TROE
Revista:
JOURNAL OF PHYSICAL CHEMISTRY A
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: Washington; Año: 2014 vol. 118 p. 4880 - 4888
ISSN:
1089-5639
Resumen:
The thermal dissociation of C3F6 was studied between 1330 and 2210 K in shock waves monitoring the UV absorption of CF2. CF2 yields of about 2.6 per parent C3F6 were obtained  at reactant concentrations of 500 ¨C 1000 ppm in the bath gas Ar. These yields dropped to about 1.8 when reactant concentrations were lowered to 60 ppm. The increase of the CF2 yield with increasing concentration was attributed to bimolecular reactions between primary and secondary dissociation products. Quantum-chemical and kinetic modeling calculations helped to estimate the contributions from the various primary dissociation steps. It was shown that the measurements correspond to unimolecular reactions in their falloff range. Falloff representations of the rate constants are given, leading to an overall high pressure rateconstant k¡Þ = 2.0 x 1017 (-104 kcal mol-1/RT) s-1 and a relative rate of about 2/3 : 1/3 for the reactions C3F6 = CF3CF + CF2 vs C3F6 = C2F3+ CF3.3F6 was studied between 1330 and 2210 K in shock waves monitoring the UV absorption of CF2. CF2 yields of about 2.6 per parent C3F6 were obtained  at reactant concentrations of 500 ¨C 1000 ppm in the bath gas Ar. These yields dropped to about 1.8 when reactant concentrations were lowered to 60 ppm. The increase of the CF2 yield with increasing concentration was attributed to bimolecular reactions between primary and secondary dissociation products. Quantum-chemical and kinetic modeling calculations helped to estimate the contributions from the various primary dissociation steps. It was shown that the measurements correspond to unimolecular reactions in their falloff range. Falloff representations of the rate constants are given, leading to an overall high pressure rateconstant k¡Þ = 2.0 x 1017 (-104 kcal mol-1/RT) s-1 and a relative rate of about 2/3 : 1/3 for the reactions C3F6 = CF3CF + CF2 vs C3F6 = C2F3+ CF3.