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Updated: May 21, 2025

Characterization, Quantification and Compound-specific Isotopic Analysis of Pyrogenic Carbon Using Benzene Polycarboxylic Acids BPCA
Published on: May 16, 2016
Modeling Carbon Basicity
Robert Fraczkiewicz1, Marvin Waldman1
1Life Sciences, Simulations Plus, Inc., 42505 10th Street West, Lancaster, CA, 93534, USA.
Abstract:
This work presents a predictive model of aqueous ionization constants (pKa) of protonatable carbons in certain aromatic rings. The phenomenon of carbon atoms sometimes acting as a stable and reversible base accepting a proton in water solution is surprisingly little recognized in medicinal chemistry, although known to general chemists for the past 60+years. We present the development and results for two predictive models: 1) identifying the most basic carbon in a ring, and 2) calculating the resulting microscopic pKa value. Both models were incorporated into our global (i. e., taking all ionizable groups into account) S+pKa model.[1-2].
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