OC1C[C@H](c2ccccc2)C2(C(O)c3ccccc3C2O)[C@@H](c2ccccc2)C1
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?