O=C1NC(=O)C(=NNc2ccc(C(=O)c3ccccc3)cc2)C(=O)N1
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?