O=C(O)C(=O)O.c1cc2nc(C34CC5CC(CC(C5)C3)C4)nc-2c[nH]1
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?