Advanced search
1 file | 1.35 MB

Theoretical study of the thermal decomposition of dimethyl disulfide

Aäron Vandeputte (UGent) , Marie-Françoise Reyniers (UGent) and Guy Marin (UGent)
(2010) JOURNAL OF PHYSICAL CHEMISTRY A. 114(39). p.10531-10549
Author
Organization
Project
HPC-UGent: the central High Performance Computing infrastructure of Ghent University
Abstract
Despite its use in a wide variety of industrially important thermochemical processes, little is known about the thermal decomposition mechanism of dimethyl disulfide (DMDS). To obtain more insight, the radical decomposition mechanism of DMDS is studied theoretically and a kinetic model is developed accounting for the formation of all the decomposition products observed in the experimental studies available in literature. Thermochemical data and rate coefficients are obtained using the high-level CBS-QB3 composite method. Among five methods tested (BMK/6-311G(2d,d,p), MPW1PW91/6-311G(2d,d,p), G3, G3B3, and CBS-QB3), the CBS-QB3 method was found to reproduce most accurately the experimental standard enthalpies of formation for a set of 17 small organosulfur compounds and the bond dissociation energies for a set of 10 sulfur bonds. Enthalpies of formation were predicted within 4 kJ mol(-1) while the mean absolute deviation on the bond dissociation enthalpies amounts to 7 kJ mol(-1). From the theoretical study, a new reaction path is identified for the formation of carbon disulfide via dithiirane (CH2S2). A reaction mechanism was constructed containing 36 reactions among 25 species accounting for the formation of all the decomposition products reported in literature. High-pressure limit rate coefficients for the 36 reactions in the reaction mechanism are presented. The kinetic model is able to grasp the experimental observations. With the recombination of thiyl radicals treated as being in the low-pressure limit, the experimentally reported first-order rate coefficients for the decomposition of DMDS are reproduced within 1 order of magnitude, while the observed product selectivities of most compounds are reproduced satisfactory. Simulations indicate that at high conversions most of the carbon disulfide forms according to the newly identified reaction path involving the formation of dithiirane.
Keywords
AB-INITIO MO, DENSITY-FUNCTIONAL GEOMETRIES, GROUP ADDITIVITY, THERMOCHEMICAL PROPERTIES, TRANSITION-STATE THEORY, BOND-DISSOCIATION ENTHALPIES, GAS-PHASE THERMOLYSIS, SUPPORTED HYDROTREATING CATALYSTS, VARIABLE REACTION COORDINATE, REACTION-RATE PREDICTION

Downloads

  • (...).pdf
    • full text
    • |
    • UGent only
    • |
    • PDF
    • |
    • 1.35 MB

Citation

Please use this url to cite or link to this publication:

Chicago
Vandeputte, Aäron, Marie-Françoise Reyniers, and Guy Marin. 2010. “Theoretical Study of the Thermal Decomposition of Dimethyl Disulfide.” Journal of Physical Chemistry A 114 (39): 10531–10549.
APA
Vandeputte, Aäron, Reyniers, M.-F., & Marin, G. (2010). Theoretical study of the thermal decomposition of dimethyl disulfide. JOURNAL OF PHYSICAL CHEMISTRY A, 114(39), 10531–10549.
Vancouver
1.
Vandeputte A, Reyniers M-F, Marin G. Theoretical study of the thermal decomposition of dimethyl disulfide. JOURNAL OF PHYSICAL CHEMISTRY A. 2010;114(39):10531–49.
MLA
Vandeputte, Aäron, Marie-Françoise Reyniers, and Guy Marin. “Theoretical Study of the Thermal Decomposition of Dimethyl Disulfide.” JOURNAL OF PHYSICAL CHEMISTRY A 114.39 (2010): 10531–10549. Print.
@article{1081472,
  abstract     = {Despite its use in a wide variety of industrially important thermochemical processes, little is known about the thermal decomposition mechanism of dimethyl disulfide (DMDS). To obtain more insight, the radical decomposition mechanism of DMDS is studied theoretically and a kinetic model is developed accounting for the formation of all the decomposition products observed in the experimental studies available in literature. Thermochemical data and rate coefficients are obtained using the high-level CBS-QB3 composite method. Among five methods tested (BMK/6-311G(2d,d,p), MPW1PW91/6-311G(2d,d,p), G3, G3B3, and CBS-QB3), the CBS-QB3 method was found to reproduce most accurately the experimental standard enthalpies of formation for a set of 17 small organosulfur compounds and the bond dissociation energies for a set of 10 sulfur bonds. Enthalpies of formation were predicted within 4 kJ mol(-1) while the mean absolute deviation on the bond dissociation enthalpies amounts to 7 kJ mol(-1). From the theoretical study, a new reaction path is identified for the formation of carbon disulfide via dithiirane (CH2S2). A reaction mechanism was constructed containing 36 reactions among 25 species accounting for the formation of all the decomposition products reported in literature. High-pressure limit rate coefficients for the 36 reactions in the reaction mechanism are presented. The kinetic model is able to grasp the experimental observations. With the recombination of thiyl radicals treated as being in the low-pressure limit, the experimentally reported first-order rate coefficients for the decomposition of DMDS are reproduced within 1 order of magnitude, while the observed product selectivities of most compounds are reproduced satisfactory. Simulations indicate that at high conversions most of the carbon disulfide forms according to the newly identified reaction path involving the formation of dithiirane.},
  author       = {Vandeputte, A{\"a}ron and Reyniers, Marie-Fran\c{c}oise and Marin, Guy},
  issn         = {1089-5639},
  journal      = {JOURNAL OF PHYSICAL CHEMISTRY A},
  keyword      = {AB-INITIO MO,DENSITY-FUNCTIONAL GEOMETRIES,GROUP ADDITIVITY,THERMOCHEMICAL PROPERTIES,TRANSITION-STATE THEORY,BOND-DISSOCIATION ENTHALPIES,GAS-PHASE THERMOLYSIS,SUPPORTED HYDROTREATING CATALYSTS,VARIABLE REACTION COORDINATE,REACTION-RATE PREDICTION},
  language     = {eng},
  number       = {39},
  pages        = {10531--10549},
  title        = {Theoretical study of the thermal decomposition of dimethyl disulfide},
  url          = {http://dx.doi.org/10.1021/jp103357z},
  volume       = {114},
  year         = {2010},
}

Altmetric
View in Altmetric
Web of Science
Times cited: