O=C(Cn1cc(COc2ccc(C(=O)c3ccccc3)cc2)nn1)c1ccc(O)cc1
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?