O=C(Nc1cccc2ccccc12)c1[nH]c(-c2ccccc2)c2c1C(=O)N(C1CC1)C2=O
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?