Nc1nc(Cl)cc(N2CCC(c3cc(-c4ccc(Cl)cc4Cl)[nH]n3)CC2)n1
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?