O=C(CSc1nc2c([nH]c3ccccc32)c(=O)n1-c1ccccc1)Nc1ccc(Cl)c(Cl)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?