O=[N+]([O-])c1cc(C(F)(F)F)cc([N+](=O)[O-])c1NCCN=C(S)Nc1ccc(Cl)c(Cl)c1
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?