O=c1[nH]c2cc([N+](=O)[O-])ccc2nc1/C(=N\NO)C(O)c1ccc([N+](=O)[O-])cc1
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?