CC1SC(c2ccccc2)N(CC(O)c2ccc([N+](=O)[O-])cc2)C1=O
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?