COc1ccc(-c2cc(C(F)(F)F)nc(SCCC(=O)Nc3cccc(OC)c3)n2)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?