| dc.creator | Cobos, Carlos Jorge | |
| dc.creator | Sölter, Lars | |
| dc.creator | Tellbach, Elsa | |
| dc.creator | Troe, J. | |
| dc.date | 2021-10 | |
| dc.date | 2022-03-23T14:47:57Z | |
| dc.date.accessioned | 2023-07-15T04:43:23Z | |
| dc.date.available | 2023-07-15T04:43:23Z | |
| dc.identifier | http://sedici.unlp.edu.ar/handle/10915/133175 | |
| dc.identifier | issn:1463-9084 | |
| dc.identifier | issn:1463-9076 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/7470636 | |
| dc.description | The 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.description | Facultad de Ciencias Exactas | |
| dc.description | Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas | |
| dc.format | application/pdf | |
| dc.format | 22437-22442 | |
| dc.language | en | |
| dc.rights | http://creativecommons.org/licenses/by-nc/3.0/ | |
| dc.rights | Creative Commons Attribution-NonCommercial 3.0 Unported (CC BY-NC 3.0) | |
| dc.subject | Física | |
| dc.subject | unimolecular dissociation | |
| dc.subject | spectroscopic and kinetic properties | |
| dc.title | Shock wave and modelling study of the unimolecular dissociation of Si(CH₃)₂F₂: an access to spectroscopic and kinetic properties of SiF₂ | |
| dc.type | Articulo | |
| dc.type | Articulo | |
