O=C(NCc1ccccc1Cl)c1ccc2[nH]c([C@@H]3O[C@H](CO)[C@@H](O)[C@H]3O)nc2c1
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?