Cc1ccc(C(=O)Nc2nc(-c3nnn(-c4cccc(Cl)c4C)c3C)ns2)cc1C
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?