O=C(CC1C(=O)N(c2ccc(Cl)cc2)C(=S)N1CCc1ccncc1)Nc1ccc(F)cc1
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?