title: Formation of the diphenyl molecule in the crossed beam reaction of phenyl radicals with benzene.
abstract: The chemical dynamics to form the D5-diphenyl molecule, C6H5C6D5, via the neutral-neutral reaction of phenyl radicals (C6H5) with D6-benzene (C6D6), was investigated in a crossed molecular beams experiment at a collision energy of 185 kJ mol(-1). The laboratory angular distribution and time-of-flight spectra of the C6H5C6D5 product were recorded at mass to charge mz of 159. Forward-convolution fitting of our data reveals that the reaction dynamics are governed by an initial addition of the phenyl radical to the pi electron density of the D6-benzene molecule yielding a short-lived C6H5C6D6 collision complex. The latter undergoes atomic deuterium elimination via a tight exit transition state located about 30 kJ mol(-1) above the separated reactants; the overall reaction to form D5-diphenyl from phenyl and D6-benzene was found to be weakly exoergic. The explicit identification of the D5-biphenyl molecules suggests that in high temperature combustion flames, a diphenyl molecule can be formed via a single collision event between a phenyl radical and a benzene molecule.
authors.affiliation: Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
authors.forename: Fangtong
authors.initials: F
authors.lastname: Zhang
authors.forename: Xibin
authors.initials: X
authors.lastname: Gu
authors.forename: Ralf I
authors.initials: RI
authors.lastname: Kaiser