COc1ccc(C2CC(O)(c3ccccc3)Oc3cc(OC)c(OC)c(OC)c32)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?