Kinetics of the reaction of chlorine atoms with isoprene (2-methyl 1,3-butadiene, CH2C(CH3)CHCH2) at 297 ± 2 K

The gas-phase reaction of chlorine atoms with isoprene was studied in 1–20 Torr of N2 or Ar diluents using pulsed laser photolysis/vacuum UV laser-induced fluorescence and in 1–700 Torr of N2 diluent using smog chamber relative rate techniques. There was no discernable effect of total pressure or nature of the diluent gas indicating that even in 1 Torr of argon diluent the reaction is near its high pressure limit. A value of k(Cl + isoprene) = (3.44 ± 0.32) × 10−10 cm3 molecule−1 s−1 was derived and is recommended for use in atmospheric models. The molar HCl yield in 700 Torr of N2 diluent was 12.6 ± 3.0%.