N=C1SC(CC(=O)Nc2ccc([N+](=O)[O-])cc2)C(=O)N1c1ccccc1
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?