C=CCN1/C(=C(\C#N)c2nc3ccccc3[nH]2)Sc2c1nc[nH]c2=O
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 negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?