CCCOc1ccc(C2C(C(=O)c3cc4ccccc4o3)=C(O)C(=O)N2c2cc(C)on2)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?