Cc1nn(C(=O)c2ccccc2O)c2c1C(c1ccc([N+](=O)[O-])cc1)SC(=N)N2
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?