COc1ccc(-c2[nH]nc3nc(-c4cc(OC)c(OC)c(OC)c4)cc(C(=O)O)c23)cc1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?