COc1cccc(C2C(C(=O)c3cc4ccccc4o3)=C(O)C(=O)N2CCN(C)C)c1OC
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?