O=C(CSCC(=O)N/N=C\c1ccc(F)cc1F)N/N=C\c1ccc(F)cc1F
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?