O=C(Nc1cc(Cl)cc(Cl)c1)C1C2C=CC3(O2)C1C(=O)N(CCCN1CCOCC1)C3C(=O)NC1CCCCC1
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?