Cc1c(NC(=O)c2ccc(-c3cccc([N+](=O)[O-])c3)o2)cccc1-c1nc2cc(Cl)ccc2o1
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 pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?