Henry's law constants of some beta-, gamma-, and delta-hydroxy alkyl nitrates of atmospheric interest

Organic nitrates form via the photodegradation of hydrocarbons in the tropo sphere in the presence of NO and NO2. This process competes with the chemic al cycle leading to ozone production since it sequesters both nitrogen oxid es and organic radicals. Hydroxy nitrates form via the atmospheric reaction s of alkanes and alkenes and are thought to be an important nitrogen oxides reservoir. In this study, new synthetic methods to produce beta-, gamma-, and delta-hydroxy nitrates of atmospheric interest were developed. NMR and IR spectroscopies were used to characterize these compounds. Henry's law co efficients of C-4 and C-5 hydroxy nitrates at 291 +/- 2 K were measured usi ng a dynamic equilibrium system. The solubility decreases with the organic chain length and increases with increasing distance between the nitrooxy an d hydroxy groups. Due to their large Henry's law coefficients these species will partition into droplets in the presence of clouds and fogs. Measureme nts of the OH reaction and photolysis rate coefficients are needed for an a ccurate assessment of the atmospheric lifetimes of these compounds.