Reaction Kinetics of Ground State Fluorine, F(²P), Atoms. I. Measurement of Fluorine Atom Concentrations and the Rates of Reactions F + CHF₃ and F + Cl₂ using Mass Spectrometry

Abstract

Reactions of F(2P) atoms generated by a 2.45 GHz discharge in dilute F2 + He mixtures have been studied mass spectrometrically with a beam inlet system from a fast flow reactor. F atom concentrations have been measured from the consumption of Cl2 in the simple and extremely rapid bimolecular reaction 1[Formula: see text]k1 was determined to be (1.1 ± 0.3) × 10−10 cm3 molecule−1 s−1 at 300 °K.Rate measurements for the reaction 2, which forms CF3 radicals, are reported, over the range 301 to 667 °K,[Formula: see text][Formula: see text]A less detailed survey of the rates at 298 °K of a series of reactions of F with H2, CH4, CH3Cl, CH2Cl2, and CHCl3, is also given; in these cases, the source of F was a discharge in CF4 + Ar, and [F] was measured by titration with ClNO.

The kinetics of the reaction F + H2 ? HF + H. A critical review of literature data

“…The results of the two studies of Clyne and coworkers [9,11] are in very good agreement with each other, as well as with the results of Wurzberg and Houston [5] and Stevens et al [6]. However, the error limits are much smaller in the more recent study [11] and therefore the results of this study should be preferred.…”

“…The error limits reported by Zhitneva and Pshezhetskii are Ϯ 17%, but it seems that the inaccuracy is much larger. Table I also includes the results of Bozzelli [8], which are in good agreement with the results of Wurzberg and Houston [5], Stevens et al [6], and the results of the two studies of Clyne et al [9,11]. The details of the experiments of Bozzelli are not known to us, because they were summarized in a Ph.D. thesis not available to us.…”

Hydrogen abstraction by fluorine atoms under conditions of thermal initiation: Hydrocarbons and fluorinated hydrocarbons

“…This question has also been considered in a companion article [2]. In brief, although several independent measurements have been attempted of the absolute F 4-H2 rate coefficient, the reported values extend from 4 X 10l2 to 3.8 X 1013 cm3/mole-sec [6,[19][20][21][22][23][24][25][26]. Pending clarification of this rather confused situation, we prefer not to attempt the estimation of absolute rate constants from our results.…”

Ab initio direct dynamics studies on the hydrogen abstraction reactions of CF2H2 and CF3H with F atom

“…The deviations of k(CVT/SCT)/k(Expt.) fall within the range of 1.3-2.0, 1.6-1.8, and 0.8-2.0 over the temperature range of 210-353 [10], 298-398 [12], and 301-667 K [13], respectively. In addition, the calculated activation energies of 2.86 and 2.32 kcal mol À1 are in reasonable agreement with the corresponding experimental values of 2.92 ± 0.3 and 1.89 ± 0.34 kcal mol À1 in the temperature range 298-398 and 210-353 K, respectively.…”

“…HF + CF 3 (R2) were investigated more extensively. The rate constants around 298 K [4,5,8,11] and in the temperature ranges of 298-398 K [12], 210-353 K [10], and 301-667 K [13] were reported. The agreement among these experimental results is good.…”