COc1cccc(NC(=O)CCc2nnc3n(Cc4ccccc4Cl)c(=O)c4ccccc4n23)c1
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?