O=c1cc2ncc(-c3n[nH]cc3[N+](=O)[O-])cn2[nH]1
The negative base-10 logarithmic of dissociation constant (pKa) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?