O=C(C1=NN(c2ccccc2)C2C(=O)N(c3ccccc3)C(=O)C12)c1ccccc1
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?