Dynamics of reactions between two closed-shell molecules

Reaction of limonene with F2: rate coefficient and products

The kinetics of the reaction of limonene (C10H16) with F2 has been studied using a low pressure (P = 1 Torr) and a high pressure turbulent (P = 100 Torr) flow reactor coupled with an electron impact ionization and chemical ionization mass spectrometers, respectively: F2 + Limonene → products (1). The rate constant of the title reaction was determined under pseudo-first-order conditions by monitoring either limonene or F2 decay in excess of F2 or C10H16, respectively. The reaction rate constant, k1 = (1.15 ± 0.25) × 10(-12) exp(160 ± 70)/T) was determined over the temperature range 278-360 K, independent of pressure between 1 (He) and 100 (N2) Torr. F atom and HF were found to be formed in reaction 1 , with the yields of 0.60 ± 0.13 and 0.39 ± 0.09, respectively, independent of temperature in the range 296-355 K.

Low temperature kinetics of unstable radical reactions

Recent advances in Earth and satellite based observations of molecules in interstellar environments and in planetary atmospheres have highlighted the lack of information regarding many important gas-phase formation mechanisms involving neutral species at low temperatures. Whilst significant progress has been made towards a better understanding of radical-molecule reactions in these regions, the inherent difficulties involved in the investigation of reactions between two unstable radical species have hindered progress in this area. This perspective article provides a brief review of the most common techniques applied to study radical-radical reactions below room temperature, before outlining the developments in our laboratory that have allowed us to extend such measurements to temperatures relevant to astrochemical environments. These developments will be discussed with particular emphasis on our recent investigations of the reactions of atomic nitrogen with diatomic radicals.