Kinetics of the reaction of O3 with selected benzenediols

The kinetics of the reaction of O-3 with the aromatic vicinal diols 1,2-benzenediol, 3-methyl-1,2 benzenediol, and 4-methyl-1,2-benzenediol have been investigated using a relative rate technique. The rate coefficients were determined in a 1080-L smog chamber at 298 K and I atm total pressure of synthetic air using propene and 1,3-butadiene as reference compounds. The following O-3 reaction rate coefficients (in units of cm(3) molecule(-1) s(-1)) have been Obtained: k(1,2-benzenediol) = (9.60 +/- 1.12) x 10(-18), k(3-methyl-1,2-benzenediol) = (2.81 +/- 0.23) x 10(-17), k(4-methyl-1,2-benzenediol) = (2.63 +/- 0.34) x 10(-17). Absolute measurements of the O-3 rate coefficient have also been carried out by measuring the decay of the dihydroxy compound in an dxcess Of O-3. The results from these experiments are in good agreement with the relative determinations. Atmospheric implications are discussed. (C) 2003 Wiley Periodicals, Inc.