Mass Spectrometric Study of the Reaction of a Fluorine Atom and Monocloroacetic Acid

Abstract

Using a low-pressure flow reactor, the kinetic regularities of the reaction of atomic fluorine with monochloroacetic acid at temperature T = 293 K are studied. The concentrations of the reagents are monitored by molecular beam mass spectrometry, detecting the molecular peaks of the substances. Using the published data, the value of the reaction rate constant $k = (9.6 \pm 3.8) \times {{10}^{{ - 11}}}$ cm³ molecules^–1 s^–1, which is the average value determined by comparison with the rate constants of competing reactions (k_ref), is calculated. The ratios of the rate constants k/k_ref, equal to 0.99 ± 0.12 and 0.75 ± 0.04, respectively, are determined for two competing reactions: a fluorine atom with 2-fluoroethanol and a fluorine atom with cyclohexane. The rate constants of the reaction of atomic fluorine with monochloroacetic acid are compared with the rate constants of reactions of atomic fluorine with chlorine-substituted acetic acids: dichloroacetic and trichloroacetic acids.