COc1ccc(Nc2nc3c(S(=O)(=O)c4ccc(C)cc4)nnn3c3ccsc23)cc1Cl
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?