COc1ccc(Nc2nc3c(S(=O)(=O)c4ccc(Br)cc4)nnn3c3ccsc23)c(OC)c1
The negative base-10 logarithmic of dissociation constant (pKa) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?