Experimental pKa Data

These pKa databases represent the extremely careful conversion of IUPAC's extensive compilations of experimental pKa values of organic acids and bases (in aqueous solution) from book form into fully curated computer-readable data, searchable by substructure.

Data Sources

• Base 1 (3775 molecules, 8766 pKas) Dissociation Constants of Organic Bases in Aqueous Solution, by D.D. Perin
• Acid 1 (1063 molecules, 2893 pKas) Dissociation Constants of Organic Acids in Aqueous Solution, by G. Kortum, W. Vogel and K. Andrussow
• Base 2 (4275 molecules, 7844 pKas) Dissociation Constants of Organic Bases in Aqueous Solution, Supplement 1972, by D.D. Perin
• Acid 2 (4584 molecules, 10912 pKas) Ionisation Constants of Organic Acids in Aqueous Solution, by E.P. Serjeant and Boyd Dempsey

The actual conversion process was done entirely by hand by Tony Slater of pKaData Limited to ensure accuracy and consistency. Tautomer enumeration was done using QUACPAC.

Features

The databases are delivered in both Microsoft Excel and CSV formats and can easily be merged with existing in-house databases with the IUPAC sourced data clearly identified.

• Molecule names and structures converted to SMILES
• IUPAC critical data quality assessment
• Data assigned to separate fields, e.g. ionic strength, concentration, and temperature
• Associated alphabetic data placed in separate field to numerical data (e.g. <5.3 assigned to two data fields) for enhanced search capabilities
• Full reference and method description for each record
• Ionization assignment for logD calculations