Cc1nn(-c2ccccc2)c(Cl)c1/C=C(\CC(=O)O)c1nc2ccccc2s1
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?