SRC's AOP Program

The Atmospheric Oxidation Program for Microsoft Windows (AOPWIN) estimates the rate constant for the atmospheric, gas-phase reaction between photochemically produced hydroxyl radicals and organic chemicals. It also estimates the rate constant for the gas-phase reaction between ozone and olefinic/acetylenic compounds. The rate constants estimated by the program are then used to calculate atmospheric half-lives for organic compounds based upon average atmospheric concentrations of hydroxyl radicals and ozone.

The estimation methods used by the Atmospheric Oxidation Program are based upon the structure-activity relationship (SAR) methods developed by Dr. Roger Atkinson and co-workers [Intern. J. Chem. Kinet. 19:799-828 (1987); Atmos. Environ. 29: 1685-95 (1995); Environ. Sci. Technol. 30: 329-34 (1996); Chem. Rev. 84: 437-470 (1984)]. In addition, SRC has derived some new fragment and reaction values from new experimental data.

A journal article describes the AOP Program: Meylan, W.M. and Howard, P.H. 1993. Computer estimation of the atmospheric gas-phase reaction rate of organic compounds with hydroxyl radicals and ozone. Chemosphere 26: 2293-99.

AOP comes with a database of experimental values for reaction rates with hydroxyl radicals, ozone, and nitrate radicals (780 chemicals). If the entered chemical substance matches one in the database, the experimental values are provided in the results screen. The newest version of AOP runs under Windows (3.1, 95, 98, NT) making the estimation of atmospheric oxidation rates more convenient and accurate. Methods for chemical structure input now support SMILES notations as well as chemical structures produced in popular chemical drawing programs. Enhanced features of the Windows version include batch-mode data entry and an expanded database of experimental values.

Example Entry/Results Window