Rate constants have been measured at room temperature for the reactions of
Cl atoms with formic acid and with the HOCO radical:
(R1) Cl + HCOOH --> HCl + HOCO
(R2) Cl + HOCO --> HCl + CO2
Cl atoms were generated by flash photolysis of Cl-2 and the progress of rea
ction was followed by time-resolved infrared absorption measurements using
tunable diode lasers on the CO2 that was formed either in the pair of react
ions (R1) plus (R2), or in reaction (R1) followed by
(R3) O-2 + HOCO --> HO2 + CO2
In a separate series of experiments, conditions were chosen so that the kin
etics of CO2 formation were dominated either by the rate of reaction (R1) o
r by that of reactions (R1) and (R2) combined. The results of our analysis
of these experiments yielded:
k(1) = (1.8(3) +/- 0.12) x 10(-13) cm(3) molecule(-1) s(-1)
k(2) = (4.8 +/- 1.0) x 10(-11) cm(3) molecule(-1) s(-1)
(C) 2000 John Wiley & Sons, Inc.