O=C(Nc1nc(-c2cccc3ccccc23)cs1)c1ccc2c(c1)S(=O)(=O)c1ccccc1C2=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?