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Title: Rate coefficients and product branching ratios for the oxidation of phenyl and naphthyl radicals: A theoretical RRKM-ME study

Authors:
; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1251736
Grant/Contract Number:
FG02-04ER15570; AC03-76F00098; AC02-05CH11231
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Proceedings of the Combustion Institute
Additional Journal Information:
Journal Volume: 35; Journal Issue: 2; Related Information: CHORUS Timestamp: 2017-10-28 17:08:09; Journal ID: ISSN 1540-7489
Publisher:
Elsevier
Country of Publication:
United States
Language:
English

Citation Formats

Kislov, V. V., Singh, R. I., Edwards, D. E., Mebel, A. M., and Frenklach, M. Rate coefficients and product branching ratios for the oxidation of phenyl and naphthyl radicals: A theoretical RRKM-ME study. United States: N. p., 2015. Web. doi:10.1016/j.proci.2014.06.135.
Kislov, V. V., Singh, R. I., Edwards, D. E., Mebel, A. M., & Frenklach, M. Rate coefficients and product branching ratios for the oxidation of phenyl and naphthyl radicals: A theoretical RRKM-ME study. United States. doi:10.1016/j.proci.2014.06.135.
Kislov, V. V., Singh, R. I., Edwards, D. E., Mebel, A. M., and Frenklach, M. Thu . "Rate coefficients and product branching ratios for the oxidation of phenyl and naphthyl radicals: A theoretical RRKM-ME study". United States. doi:10.1016/j.proci.2014.06.135.
@article{osti_1251736,
title = {Rate coefficients and product branching ratios for the oxidation of phenyl and naphthyl radicals: A theoretical RRKM-ME study},
author = {Kislov, V. V. and Singh, R. I. and Edwards, D. E. and Mebel, A. M. and Frenklach, M.},
abstractNote = {},
doi = {10.1016/j.proci.2014.06.135},
journal = {Proceedings of the Combustion Institute},
number = 2,
volume = 35,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 2015},
month = {Thu Jan 01 00:00:00 EST 2015}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.proci.2014.06.135

Citation Metrics:
Cited by: 9works
Citation information provided by
Web of Science

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  • Ab initio CCSD(T)/CBS//B3LYP/6-311G** calculations of the potential energy surface for possible dissociation channels of the phenyl radical are combined with microcanonical Rice-Ramsperger-Kassel-Marcus calculations of reaction rate constants in order to predict statistical product branching ratios in photodissociation of c-C{sub 6}H{sub 5} at various wavelengths. The results indicate that at 248 nm the photodissociation process is dominated by the production of ortho-benzyne via direct elimination of a hydrogen atom from the phenyl radical. At 193 nm, the statistical branching ratios are computed to be 63.4%, 21.1%, and 14.4% for the o-C{sub 6}H{sub 4}+ H, l-C{sub 6}H{sub 4} ((Z)-hexa-3-ene-1,5-diyne) + H, andmore » n-C{sub 4}H{sub 3}+ C{sub 2}H{sub 2} products, respectively, in a contradiction with recent experimental measurements, which showed C{sub 4}H{sub 3}+ C{sub 2}H{sub 2} as the major product. Although two lower energy pathways to the i-C{sub 4}H{sub 3}+ C{sub 2}H{sub 2} products are identified, they appeared to be kinetically unfavorable and the computed statistical branching ratio of i-C{sub 4}H{sub 3}+ C{sub 2}H{sub 2} does not exceed 1%. To explain the disagreement with experiment, we optimized conical intersections between the ground and the first excited electronic states of C{sub 6}H{sub 5} and, based on their structures and energies, suggested the following photodissociation mechanism at 193 nm: c-C{sub 6}H{sub 5} 1{yields} absorption of a photon {yields} electronically excited 1{yields} internal conversion to the lowest excited state {yields} conversion to the ground electronic state via conical intersections at CI-2 or CI-3{yields} non-statistical decay of the vibrationally excited radical favoring the formation of the n-C{sub 4}H{sub 3}+ C{sub 2}H{sub 2} products. This scenario can be attained if the intramolecular vibrational redistribution in the CI-2 or CI-3 structures in the ground electronic state is slower than their dissociation to n-C{sub 4}H{sub 3}+ C{sub 2}H{sub 2} driven by the dynamical preference.« less
  • A high yield route (80-90%) to the bridging dinitrogen complex (WCp{sup *}Me{sub 3}){sub 2}({mu}-N{sub 2}) (1) consists of the reduction of WCp{sup *}Me{sub 3}(OTf) by sodium amalgam in the presence of dinitrogen. 1 reacts with HOTf (2 or excess (6) equiv) to give (WCp{sup *}Me{sub 2}(OTf)){sub 2}({mu}-N{sub 2}) or (WCp{sup *}Me(OTf){sub 2}){sub 2}({mu}-N{sub 2}), respectively, with C{sub 6}F{sub 5}COOH, C{sub 6}F{sub 5}OH, or C{sub 6}F{sub 5}SH to give complexes of the form (WCp{sup *}Me{sub 2}(X)){sub 2}({mu}-N{sub 2}) (X = OC{sub 6}F{sub 5}, etc.), and with tetrabromocatechol to give (WCp{sup *}Me(O{sub 2}C{sub 6}Br{sub 4})){sub 2}({mu}-N{sub 2}). (WCp{sup *}Me{sub 2}(OTf)){sub 2}({mu}-N{sub 2})more » reacts with NaSR (R = 2,4,6-C{sub 6}H{sub 2}Me{sub 3} or 2,4,6-C{sub 6}H{sub 2}-i-Pr{sub 3}) to give complexes of the form (WCp{sup *}Me{sub 2}(SR)){sub 2}({mu}-N{sub 2}), and (WCp{sup *}Me(OTf){sub 2}){sub 2}({mu}-N{sub 2}) and (WCp{sup *}Me{sub 2}(S-2,4,6-C{sub 6}H{sub 2}Me{sub 3})){sub 2}({mu}-N{sub 2}) show that the complexes have structures that are similar to that of 1, except the N-N bond lengths are shorter.« less
  • The paper describes a general method for determining absolute branching ratios in mass spectrometric experiments. The method overcomes the chronic obstacle that the daughter ion fragmentation pattern of radical products is usually unknown. We report the absolute product branching ratio for competing primary C-Cl and C-C bond fission in chloroacetone after excitation on the {sup 1}n{pi}{sup *} absorption band. To determine this branching ratio, acetyl chloride is used to calibrate the relative detection efficiency of acetyl radicals at the CH{sub 2}CO{sup +} daughter ion relative to Cl atoms at {sup 35}Cl. We also calculate the daughter ion production probability formore » CH{sub 2}CO{sup +} formed from internally excited CH{sub 3}CO radicals. 17 refs., 5 figs.« less