CCn1nc(C)c(CN2CCC(C(=O)Nc3cccc(-c4cccc(Cl)c4)c3)CC2)c1C
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?