COc1ccc(-n2nc(C(=O)NCC(=O)N3CCN(Cc4ccccc4)CC3)c3ccccc3c2=O)cc1OC
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?