COc1cc(C2C(C(=O)Nc3ccc([N+](=O)[O-])cc3)=C(C)NC(C)=C2C(=O)Nc2ccc([N+](=O)[O-])cc2)ccc1O
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?