CC1=NN(c2ccccc2Cl)C2(C1)C(Cl)C(=O)N2c1nc2ccccc2s1
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?