COc1ccc(Cn2c(=O)[nH]c3cc(C(=O)N4CCN(C(=O)c5ccco5)CC4)ccc3c2=O)cc1
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?