O=C(NNC(=O)c1cccnc1SCc1cccc([N+](=O)[O-])c1)c1ccc(F)cc1
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?