Cc1ccc(O)c(C2=Nc3ccccc3N=C(c3cccc([N+](=O)[O-])c3)C2)c1
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?