Falloff curves and mechanism of thermal decomposition of CF₃I in shock waves

The falloff curves of the unimolecular dissociation CF₃I (+Ar) → CF₃ + I (+Ar) are modelled by combining quantum-chemical characterizations of the potential energy surface for the reaction, standard unimolecular rate theory, and experimental information on the average energy transferred per collisio...

Full description

Bibliographic Details
Authors: Cobos, Carlos Jorge, Sölter, L., Tellbach, E., Troe, J.
Format: article
Status:Published version
Publication Date:2019
Country:Argentina
Institution:Universidad Nacional de La Plata
Repository:SEDICI (UNLP)
Language:English
OAI Identifier:oai:sedici.unlp.edu.ar:10915/138272
Online Access:http://sedici.unlp.edu.ar/handle/10915/138272
Access Level:Open access
Keyword:Física
Química
Falloff curves
Unimolecular dissociation
Decomposition mechanism
Description
Summary:The falloff curves of the unimolecular dissociation CF₃I (+Ar) → CF₃ + I (+Ar) are modelled by combining quantum-chemical characterizations of the potential energy surface for the reaction, standard unimolecular rate theory, and experimental information on the average energy transferred per collision between excited CF₃I and Ar. The (essentially) parameter-free theoretical modelling gives results in satisfactory agreement with data deduced from earlier shock wave experiments employing a variety of reactant concentrations (between a few ppm and a few percent in the bath gas Ar). New experiments recording absorption-time signals of CF₃I, I₂, CF₂ and (possibly) IF at 450-500 and 200-300 nm are reported. By analysing the decomposition mechanism, besides the unimolecular dissociation of CF₃I, these provide insight into the influence of secondary reactions on the experimental observations.