Kinetic study of the vapour-phase reaction between aliphatic aldehydes and the nitrate radical

Abstract

Vapour-phase rate coefficients for the reaction of the nitrate radical with seven aliphatic aldehydes have been determined at 298±2 K and 1013±10 mbar by the relative rate method using FTIR detection. The obtained rate coefficients, in units of 10^-14 cm³ molecule^-1 s^-1 and with 3σ statistical errors, are: propanal, 0.57±0.04; butanal, 1.09±0.08; pentanal, 1.46±0.09; hexanal, 1.73±0.18; 2-methylpropanal, 1.21±0.06; 2,2-dimethylpropanal, 2.29±0.09; and 3,3-dimethylbutanal, 2.00±0.14. The existing rate coefficients for NO₃ and OH reactions with aldehydes are compared and it is suggested that the reaction between NO₃ and aldehydes is not a simple hydrogen abstraction.