dc.creatorCobos, Carlos Jorge
dc.creatorSölter, Lars
dc.creatorTellbach, Elsa
dc.creatorTroe, J.
dc.date2021-10
dc.date2022-03-23T14:47:57Z
dc.date.accessioned2023-07-15T04:43:23Z
dc.date.available2023-07-15T04:43:23Z
dc.identifierhttp://sedici.unlp.edu.ar/handle/10915/133175
dc.identifierissn:1463-9084
dc.identifierissn:1463-9076
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/7470636
dc.descriptionThe thermal dissociation of Si(CH₃)₂F₂ was studied in shock waves between 1400 and 1900 K. UV absorption-time profiles of its dissociation products SiF₂ and CH₃ were monitored. The reaction proceeds as a unimolecular process not far from the high-pressure limit. Comparing modelled and experimental results, an asymmetric representation of the falloff curves was shown to be most realistic. Modelled limiting high-pressure rate constants agreed well with the experimental data. The UV absorption spectrum of SiF₂ was shown to be quasi-continuous, with a maximum near 222 nm and a wavelength-integrated absorption cross section of 4.3 (±1) × 10⁻²³ cm³ (between 195 and 255 nm, base e), the latter being consistent with radiative lifetimes from the literature. Experiments over the range 1900-3200 K showed that SiF₂ was not consumed by a simple bond fission SiF₂ →SiF + F, but by a bimolecular reaction SiF₂ + SiF₂ → SiF + SiF₃ (rate constant in the range 10¹¹-10¹² cm³ mol⁻¹ s⁻¹), followed by the unimolecular dissociation SiF₃ → SiF₂ + F such that the reaction becomes catalyzed by the reactant SiF₂. The analogy to a pathway CF₂ + CF₂ → CF + CF₃, followed by CF₃ → CF₂ + F, in high-temperature fluorocarbon chemistry is stressed. Besides the high-temperature absorption cross sections of SiF₂, analogous data for SiF are also reported.
dc.descriptionFacultad de Ciencias Exactas
dc.descriptionInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
dc.formatapplication/pdf
dc.format22437-22442
dc.languageen
dc.rightshttp://creativecommons.org/licenses/by-nc/3.0/
dc.rightsCreative Commons Attribution-NonCommercial 3.0 Unported (CC BY-NC 3.0)
dc.subjectFísica
dc.subjectunimolecular dissociation
dc.subjectspectroscopic and kinetic properties
dc.titleShock wave and modelling study of the unimolecular dissociation of Si(CH₃)₂F₂: an access to spectroscopic and kinetic properties of SiF₂
dc.typeArticulo
dc.typeArticulo


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