Pyrolysis of Ethyl Iodide as Hydrogen Atom Source: Kinetics and Mechanism in the Temperature Range 950–1200 K
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Tobias Bentz
Abstract
Ethyl iodide is a well known H atom precursor in shock tube experiments. In the present work, we study peculiarities, when C2H5I is used under conditions, where its decomposition is not longer fast compared to consecutive bimolecular reactions. On the basis of shock tube experiments with detection of H and I atoms by resonance absorption spectrometry, accompanied by quantum chemical (CCSD(T)/6-311G//CCSD/6-311G) and statistical rate theory calculations, we propose a small mechanism (5 reactions, 7 species) and kinetic data, which allow an adequate description of C2H5I pyrolysis as a H atom source down to temperatures between 950 and 1200 K at pressures ranging from 1 to 4 bar: C2H5I→C2H5 + I (1), k1 = 9.9 × 1012 exp(−23200 K/T) s−1; C2H5 + M→C 2H4 + H + M (2), k2 = 1.7 × 10−6 exp(−16800 KT) cm3 s−1 [D. L. Baulch et al., J. Phys. Chem. Ref. Data 34 (2005) 757]; C2H5I→C2H4 + HI (3), k3 = 1.7 × 1013 exp(−26680 KT) s−1; H + HI→H2 + I (4), k4 = 7.9 × 10−11 exp(−330 KT) cm3 s−1 [D. L. Baulch et al., J. Phys. Chem. Ref. Data 10(Suppl. 1) (1981) 1]; C2H5I + H→C2H5 + HI (5), k5 = 7.0 × 10−9 exp(−3940 KT) cm3 s−1. The latter bimolecular abstraction step turned out crucial for an adaquate d escription of the hydrogen atom concentration-time profiles in the above mentioned temperature and pressure range for initial concentrations [C2H5I]0 > 2 × 1013 cm−3 corresponding to mole fractions > 1 ppm.
© by Oldenbourg Wissenschaftsverlag, Karlsruhe, Germany
Articles in the same Issue
- Preface
- OH and NH Stretching Vibrational Relaxation of Liquid Ethanolamine
- Transient anisotropy in degenerate systems: A semi-classical approach
- First Cavity Ring-Down Spectroscopy HO2 Measurements in a Large Photoreactor
- Relaxation Dynamics of Electronically Excited C60− in o-Dichlorobenzene and Tetrahydrofuran Solution
- 3CH2 + O2: Kinetics and Product Channel Branching Ratios
- What Do We Know About the Iconic System CH3 + CH3 + M ↔ C2H6 + M?
- Thermochemistry and Kinetics for 2-Butanone-3yl Radical (CH3C(=O)CH•CH3) Reactions with O2
- Experimental and Modelling Study of the Unimolecular Thermal Decompostion of CHF3
- Combustion Chemistry of the Butane Isomers in Premixed Low-Pressure Flames
- Characterization of Rhodamine 6G Release in Electrospray Ionization by Means of Spatially Resolved Fluorescence Spectroscopy
- Femtosecond interferometry of molecular dynamics – the role of relative and absolute phase of two individual laser pulses
- Photodecarbonylation of Diphenylcyclopropenone – a Direct Pathway to Electronically Excited Diphenylacetylene?
- Yield of HO2 Radicals in the OH-Initiated Oxidation of SO2
- Pyrolysis of Ethyl Iodide as Hydrogen Atom Source: Kinetics and Mechanism in the Temperature Range 950–1200 K
- Reaction of OH and NO at Low Temperatures in the Presence of Water: the Role of Clusters
Articles in the same Issue
- Preface
- OH and NH Stretching Vibrational Relaxation of Liquid Ethanolamine
- Transient anisotropy in degenerate systems: A semi-classical approach
- First Cavity Ring-Down Spectroscopy HO2 Measurements in a Large Photoreactor
- Relaxation Dynamics of Electronically Excited C60− in o-Dichlorobenzene and Tetrahydrofuran Solution
- 3CH2 + O2: Kinetics and Product Channel Branching Ratios
- What Do We Know About the Iconic System CH3 + CH3 + M ↔ C2H6 + M?
- Thermochemistry and Kinetics for 2-Butanone-3yl Radical (CH3C(=O)CH•CH3) Reactions with O2
- Experimental and Modelling Study of the Unimolecular Thermal Decompostion of CHF3
- Combustion Chemistry of the Butane Isomers in Premixed Low-Pressure Flames
- Characterization of Rhodamine 6G Release in Electrospray Ionization by Means of Spatially Resolved Fluorescence Spectroscopy
- Femtosecond interferometry of molecular dynamics – the role of relative and absolute phase of two individual laser pulses
- Photodecarbonylation of Diphenylcyclopropenone – a Direct Pathway to Electronically Excited Diphenylacetylene?
- Yield of HO2 Radicals in the OH-Initiated Oxidation of SO2
- Pyrolysis of Ethyl Iodide as Hydrogen Atom Source: Kinetics and Mechanism in the Temperature Range 950–1200 K
- Reaction of OH and NO at Low Temperatures in the Presence of Water: the Role of Clusters
