COc1ccc(NC(=O)Cn2c(=O)n(Cc3ccc(C(=O)NCc4ccccc4Cl)cc3)c(=O)c3ccccc32)cc1OC
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?