COC(=O)c1ccc(/C=C(\c2ccc([N+](=O)[O-])o2)S(=O)(=O)c2ccc(NC(C)=O)cc2)o1
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?