O=C(CN1CCCN(Cc2cccc(Cl)c2)S1(=O)=O)Nc1ccc2c(c1)OCCO2
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?