Theoretical and experimental study of the OH radical reaction with HCN

Abstract

The reaction rates of OH with H13CN and HC15N have been measured relative to that with H12C14N at 298 ± 2 K and 1013 ± 10 hPa in purified air by long-path FTIR spectroscopy; the 12C/13C and 14N/15N kinetic isotope effects were determined to be 0.9733 ± 0.0012 and 0.9840 ± 0.0016 (1σ), respectively. Ground-state potential energy hyper-surfaces of the reaction were investigated by quantum chemistry methods according to which the HCN + OH reaction proceeds via addition of OH to the carbon atom with a barrier height of 15.4 kJ mol−1. Master equation modelling of the reaction rate coefficient and kinetic isotope effects show good agreement with the experiments.