O=C(Cn1cc(S(=O)(=O)c2ccccc2)c(=O)c2cc3c(cc21)OCO3)Nc1ccccc1
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?