COc1cc(/C=C2/C(=O)c3cccc([N+](=O)[O-])c3C2=O)c(Br)cc1O
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?