COc1ccc(C2CC3=Nc4ccccc4N(C(=O)CCC(=O)O)C(c4ccc(F)cc4)C3=C(O)C2)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?