O=C1c2[nH]nc(-c3ccccc3O)c2C(c2cccc(OCc3ccccc3)c2)N1CCCO
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?