We critically compiled the experimental values of logPN, pKa, logP I app , and logDpH of 225 entries based on earlier literature reports (database available in reference 33). Refs. 29 and 55 were chosen based on the wide selection of experimental data for logPN, logDpH, and logPI values and because they encompass the desired chemical space of small molecules for our modeling. SMILES codes were collected from publicly available data in PubChem. The experimental pKa values were also obtained from PubChem, but they were corroborated by reviewing their values in primary literature reports. The experimental technique of logPN, logDpH, and logP I app measurements for each entry were thoroughly revised and added to the database. The logPI values were obtained from the logDpH at the most extreme measured pH, in which the molecule would be mostly (above 95 %) in its ionized state. The logP I app values for molecules that were not measured under ionizable pH conditions were obtained from external sources. The molecules were classified as acids or bases based on their functional groups and pKa values.