Prediction of aqueous diffusion coefficients for organic compounds at 25°C

Correlations for the prediction of aqueous diffusion coefficients from molecular connectivity indices (MCIs) were developed using data for 108 organic compounds at 25°C. A good correlation between MCIs and aqueous diffusion coefficients was observed for the entire data set. Some correlations improved when the compounds were divided into specific chemical classes. Aqueous diffusion coefficients predicted using MCIs were compared statistically (r2 and mean percent difference) to values calculated using molar volume and alkyl chain length estimation methods. Based on mean percent difference, the MCI-based estimation methods were as good as or better than the molar volume and alkyl chain length methods.