COc1cccc(Nc2nnc(SCC(=O)N3CC(=O)Nc4ccccc43)s2)c1
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?