O=S(=O)(c1ccc2c(c1)OCCO2)N1CCC(c2nc3cc(Cl)ccc3[nH]2)CC1
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?