Rates of reaction between the nitrate radical and some aliphatic esters

Rate coefficients for the reaction of NO3 with methyl formate, methyl acetate, methyl propionate, methyl butylrate, ethyl formate, ethyl acetate, ethyl propionate, propyl formate, propyl acetate and n-hexane have been determined at 296 ± 2 K. The rate coefficients, which should strictly be interpreted as upper limits, were found to be 0.36 ± 0.08, 0.7 ± 0.2, 3.3 ± 0.8, 4.8 ± 0.5, 1.7 ± 0.3, 1.3 ± 0.3, 3.3 ± 0.4, 5.4 ± 0.9, 5 ± 2 and 14.7 ± 3.0, respectively (in units of 10–17 cm3 molecule–1 s–1). The activation energy for the reaction between ethyl acetate and NO3 was determined to be 23 ± 8 kJ mol–1 between 273 and 373 K. The rate coefficients for aliphatic esters may be predicted from available group reactivity factors for alkanes provided that formate carbonyl hydrogen atoms are treated as primary hydrogen atoms.