CCN1C(=O)/C(=C\c2ccc(-c3ccc([N+](=O)[O-])cc3OC)o2)S/C1=N\c1cccc(C(=O)O)c1
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?