%0 Journal Article %T Isomerization and dissociation of n-butylbenzene radical cation. %+ Laboratoire des mécanismes réactionnels (DCMR) %A Halbert, Stephanie %A Bouchoux, Guy %< avec comité de lecture %@ 1089-5639 %J Journal of Physical Chemistry A %I American Chemical Society %V 116 %N 4 %P 1307-1315 %8 2012-02-02 %D 2012 %R 10.1021/jp211673f %M 22229805 %Z Chemical Sciences/Theoretical and/or physical chemistryJournal articles %X Fragmentation mechanisms of ionized butylbenzene to give m/z 91 and m/z 92 fragment ions have been examined at the G3B3 and G3MP2B3 levels of theory. It is shown that the energetically favored pathways lead to tropylium, Tr(+), and methylene-2,4-cyclohexadiene, MCD(*+), ions. Formation of m/z 91 benzyl ions, Bz(+), by a simple bond fission (SBF) process, needs about 30 kJ/mol more energy than Tr(+). Possible formation of C(7)H(8)(*+) ions of structures different from the retro-ene rearrangement (RER) product, MCD(*+), has been also considered. Comparison with experimental data of this "thermometer" system is done through a kinetic modeling using Rice-Ramsperger-Kassel-Marcus (RRKM) and orbiting transition state (OTS) rate constant calculations on the G3MP2B3 0 K energy surface. The results agree with previous experimental observation if (i) the competitive formation of Tr(+) and Bz(+) is taken into account in the m/z 91 pathway, and (ii) the stepwise character of the RER fragmentation is introduced in the m/z 92 fragmentation route. %G English %L hal-00904400 %U https://polytechnique.hal.science/hal-00904400 %~ X %~ CNRS %~ X-DCMR %~ X-DEP %~ X-DEP-CHIM %~ INC-CNRS