O=C(/C=C/c1ccccc1)Nc1cc(NC(=O)/C=C/c2ccccc2)cc(C(=O)O)c1
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?