COc1ccc(NC(=O)CSc2ncc3c(n2)-c2ccccc2N(Cc2ccc(C)cc2)S3(=O)=O)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?