CCN1C(=O)C2(C(C#N)=C(N)Oc3[nH]nc(-c4ccc(Cl)cc4)c32)c2ccccc21
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?