COc1cccc(/C=C/C(=O)OCC(=O)Nc2ccc(S(=O)(=O)N3CCCC3)cc2)c1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?