화학공학소재연구정보센터
Journal of Physical Chemistry, Vol.100, No.25, 10641-10645, 1996
Reactivity of Negative-Ions with Trifluoromethyl Halides
The kinetics of reactions of selected anions (A(-)) with the trifluoromethyl halides CF(3)X (X = F, Cl, Br, I) in the gas phase were measured at 300 K. Reaction rate constants and product branching fractions were determined using a selected ion flow tube (SIFT) instrument. The chosen anions were C5F5N-, o-, m-, and p-CF3C6H4CN-, C6F5Br-, C6F5Cl-, C6F5CF3-, C6F5COCH3-, Fe-, FeCO-, SF6-, SO-, SO2-, NO-, NO2-, and NO3-. The reactivity of these systems varies from unreactive to collisional, and a variety of reaction types was found. The results of our present and previous measurements on A(-) + CF(3)X reactions show that, in cases where nondissociative electron transfer (NDET) is energetically allowed, the total reactivity tends to be high, approaching collisional. This suggests that reactivity in these cases is initiated and controlled by electron transfer from the anion. In addition, association reactions tend to be preempted when NDET is energetically allowed. A few exceptions to these tendencies were found and are discussed.