An experimental and theoretical investigation of the formation of C7H7 isomers in the bimolecular reaction of dicarbon molecules with 1,3-pentadiene

We report on the crossed molecular beam reaction of dicarbon, C-2 (X-1 Sigma(+)(g), a(3) Pi u), with 1,3-pentadiene (C5H8; X(1)A') conducted at a collision energy of 43 kJ mol (1) under single collision conditions and studied by ab initio and statistical calculations. The reactions involve indirect scattering dynamics initiated by the barrierless addition of dicarbon to the carbon-carbon double bond of 1,3-pentadiene followed by successive rearrangements leading eventually through hydrogen atom elimination to distinct C7H7 radical species. The experimental reaction exoergicity of 412 +/- 52 kJ mol (1) is consistent with the formation of cycloheptatrienyl, m-tolyl, and/or benzyl radicals predicted as the major products by theory. (C) 2014 Elsevier B.V. All rights reserved.