O=C1NC(c2ccncc2)C(C(=O)c2cccs2)C(O)(C(F)(F)F)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?