COc1ccc(N2CCN(C(=O)CCS(=O)(=O)c3cc4c(cc3Cl)NC(=O)CO4)CC2)cc1
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?