COc1ccc(N2CCN(C(=O)c3oc4ccccc4c3NC(=O)c3ccccc3OC)CC2)cc1
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?