COc1ccccc1N(C)S(=O)(=O)c1ccc(Cl)c(C(=O)Nc2cccc(C)n2)c1
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?