C=CCN(C(=O)CSC1=NC(=O)CN1C(C)=O)c1nc(C)c(-c2ccccc2)s1
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?