COCCN1C(=O)c2[nH]nc(-c3ccccc3O)c2C1c1ccc(OCc2ccccc2)c(OC)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?