O=C(CSc1nc2scc(-c3ccccc3)c2c(=O)[nH]1)Nc1ccc(C(F)(F)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?