O=C(O)c1ccc(N2C(=O)CC(N3C(=O)/C(=C/c4ccc(Cl)cc4)SC3=S)C2=O)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?