Cc1cccc(NC(=O)C[S+]([O-])CC(=O)Nc2cnc3ccccc3c2)c1C
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?