O=C(C1=C(O)C(=O)N(CCN2CCOCC2)C1c1cccc(O)c1)c1cc2ccccc2o1
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?