COc1cc(/C=C/C(=O)O)cc(S(=O)(=O)Nc2ccccc2C(=O)NCc2ccco2)c1OC
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?