O=C(Cn1c2ccc(F)cc2c2nc3n(c(=O)c21)CCS3)Nc1ccc(Cl)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?