UC San Diego

Literature values for the partition of nitric oxide between the gas phase and water and between the gas phase and organic solvents have been combined to yield water-solvent partition coefficients. Analysis of the gas-solvent and water-solvent partition coefficients using the solvation equations of Abraham shows that nitric oxide has no hydrogen bond acidity at all, and is only a very weak hydrogen bond base. The various solvation descriptors of Abraham for nitric oxide can be obtained, and are shown to be similar to other inorganic gases; the descriptors can be used to predict a large number of physicochemical properties of nitric oxide. The calculated lipophilicity of nitric oxide, as a water-octanol partition coefficient, is very small at 0.58 (logP_oct), about the same as argon or nitrogen.