Structure-activity relationship for the estimation of OH-oxidation rate constants of aliphatic organic compounds in the aqueous phase: alkanes, alcohols, organic acids and bases

A robust estimation method of aqueous phase OH-oxidation rate constants of organic compounds would be of high benefit to a wide community relevant to atmospheric chemistry. Here, we propose an aqueous phase structure-reactivity relationship (SAR) for aliphatic organic compounds including alkanes, alcohols, organic acids, bases and polyfunctional compounds containing at least two of these functions. The methodology used is based on Atkinsonʹs group-addivity SAR [Atkinson, R., 1987. A structure-activity relationship for the estimation of rate constants for the gas-phase reactions of OH radicals with organic compounds. International Journal of Chemical Kinetics 19, 799–828] for the gas phase reactions, with slight differences. It is constructed using an automatic solver, and using a wide database which includes 72 aliphatic compounds, and 7 functions, for reactions studied at room temperature in the aqueous phase. The results show a satisfactory efficiency of the proposed SAR as 60% of the estimated values were found within the range of 80% of the experimental values. The obtained parameters are discussed, and the performances of the method are compared to other estimation methods.