% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Alarcn:276126,
      author       = {Alarcón, P. and Bohn, B. and Zetzsch, C.},
      title        = {{K}inetic and mechanistic study of the reaction of {OH}
                      radicals with methylated benzenes: 1,4-dimethyl-,
                      1,3,5-trimethyl-, 1,2,4,5-, 1,2,3,5- and
                      1,2,3,4-tetramethyl-, pentamethyl-, and hexamethylbenzene},
      journal      = {Physical chemistry, chemical physics},
      volume       = {17},
      number       = {19},
      issn         = {1463-9084},
      address      = {Cambridge},
      publisher    = {RSC Publ.},
      reportid     = {FZJ-2015-06603},
      pages        = {13053 - 13065},
      year         = {2015},
      abstract     = {The reaction of OH radicals with a series of methylated
                      benzenes was studied in a temperature range 300–350 K
                      using a flash-photolysis resonance fluorescence technique.
                      Reversible OH additions led to complex OH decays dependent
                      on the number of distinguishable adducts. Except for
                      hexamethylbenzene, triexponential OH decay curves were
                      obtained, consistent with formation of at least two adduct
                      species. For three compounds that can strictly form two
                      adduct isomers for symmetry reasons (1,4-dimethyl-,
                      1,3,5-trimethyl-, and 1,2,4,5-tetramethylbenzene) with OH
                      bound ortho or ipso with respect to the methyl groups, OH
                      decay curves were analysed in terms of a reaction mechanism
                      in which the two adducts can be formed directly by OH
                      addition or indirectly by isomerization. In all cases one
                      adduct (add1) is dominating the decomposition back to OH.
                      The other (add2) is more elusive and only detectable at
                      elevated temperatures, similar to the single OH adduct of
                      hexamethylbenzene. Two limiting cases of the general
                      reaction mechanism could be examined quantitatively:
                      reversible formation of add2 exclusively in the OH reaction
                      or by isomerization of add1. Total OH rate constants, adduct
                      loss rate constants and products of forward and reverse rate
                      constants of reversible reactions were determined. From
                      these quantities, adduct yields, equilibrium constants, as
                      well as reaction enthalpies and entropies were derived for
                      the three aromatics. Adduct yields strongly depend on the
                      selected reaction model but generally formation of add1
                      predominates. For both models equilibrium constants of OH
                      reactions lie between those of OH + benzene from the
                      literature and those obtained for OH + hexamethylbenzene.
                      The corresponding reaction enthalpies of add1 and add2
                      formations are in a range −87 ± 20 kJ mol−1, less
                      exothermic than for hexamethylbenzene (−101 kJ mol−1).
                      Reaction enthalpies of possible add1 → add2 isomerizations
                      are comparatively small. Because results for
                      1,3,5-trimethylbenzene are partly inconsistent with a direct
                      formation of add2, we promote the existence of isomerization
                      reactions. Moreover, based on available theoretical work in
                      the literature, add1 and add2 are tentatively identified as
                      ortho and ipso adducts, respectively. Total OH rate
                      constants were obtained for all title compounds. They can be
                      described by Arrhenius equations: kOH = A × exp(−B/T).
                      The parameters ln(A/(cm3 s−1)) = −25.6 ± 0.3, −25.3
                      ± 0.6, −27.3 ± 0.3, −24.6 ± 0.3, −26.2 ± 0.4,
                      −26.2 ± 0.4 and −24.5 ± 0.2, and B/K = −160 ± 90,
                      −550 ± 180, −1120 ± 90, −330 ± 100, −820 ± 100,
                      −980 ± 130, and −570 ± 40 were determined for
                      1,4-dimethyl-, 1,3,5-trimethyl-, 1,2,4,5-, 1,2,3,5- and
                      1,2,3,4-tetramethyl-, pentamethyl-, and hexamethylbenzene.},
      cin          = {IEK-8},
      ddc          = {540},
      cid          = {I:(DE-Juel1)IEK-8-20101013},
      pnm          = {243 - Tropospheric trace substances and their
                      transformation processes (POF3-243)},
      pid          = {G:(DE-HGF)POF3-243},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000354195300070},
      pubmed       = {pmid:25913267},
      doi          = {10.1039/C5CP00253B},
      url          = {https://juser.fz-juelich.de/record/276126},
}