COc1ccccc1C1C(C(=O)c2cc3ccccc3o2)=C(O)C(=O)N1c1cc(C)on1
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?