COc1cccc2c1Oc1ncccc1N(c1ccc(C(=O)NCc3ccccc3Cl)s1)C2
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?