CCOc1ccc(NC2=NC(=O)C(CC(=O)Nc3ccc(Cl)cc3Cl)S2)cc1
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?