Reaction of Anthracene with CH Radicals:  An Experimental Study of the Kinetics between 58 and 470 K

Abstract

The rate coefficient of the reaction of the methylidine radical CH with anthracene has been studied over a wide temperature range (58-470 K) in a dedicated "Cinétique de Réaction en Ecoulement Supersonique Uniforme" (Reaction Kinetics in Uniform Supersonic Flow) apparatus. The reaction exhibits a slight positive temperature dependence, which can be fitted to the expression k(T) = (3.32 +/- 1.00) x 10(-10)(T/298)((0.46+/-0.14)) cm3 molecule(-1) s(-1). Even at the lowest temperature, the reaction remains very fast indicating that the kinetics are probably driven by a capture process.

Insights into gas-phase reaction mechanisms of small carbon radicals using isomer-resolved product detection

“…66 A better understanding of the chemical role of the CH radical in carbon-rich environments requires differentiating between the different reaction entrance channels for a wide range of molecules and experimental conditions. In the laboratory, ground state CH radicals are produced via debromination of bromoform using 193 nm, 28 266 nm 14,59,67 or 248 nm 44,68,69 laser photolysis, reaction with potassium atoms, 57,69 or discharge-induced dissociation. 68 Photolytic and discharge dissociations, generate CH radicals with large excess vibrational energy.…”

“…68 Quenching to the ground vibrational level can be achieved by collision with a large excess of molecular nitrogen. 67,70 In the case of the reaction with potassium atoms, the CH radicals have been shown to exclusively form in the ground vibrational level. 69 For product detection studies under flow conditions, reactions of the singlet CHBr with the hydrocarbon reactant may lead to the formation of products at the same mass-over-charge ratio than that of the CH reaction products.…”

Direct detection of pyridine formation by the reaction of CH (CD) with pyrrole: a ring expansion reaction

“…5 and 6. As discussed by Goulay and coworkers, 8 it is then reasonable to assume that the mechanism of the title reaction proceeds via the addition of the radical to a double bond forming a short-lived intermediate that subsequently decomposes to give the stable product, i.e. pyridine, with the elimination of an H atom.…”

Insights into the role of polycyclic aromatic hydrocarbon condensation in haze formation in Jupiter’s atmosphere

“…We follow the same approach that was successfully developed for the study of pyrene dimerization, described previously (Sabbah et al 2010) and therefore only briefly outlined below. The experiments are performed using a continuous flow CRESU apparatus (Rowe et al 1984), adapted for condensable species such as PAHs (Goulay et al 2006). This chemical reactor is designed to generate dense uniform flows using a Laval nozzle over a wide range of temperatures (60−470 K) and containing high concentrations of PAH vapors.…”