COc1cc(C2C(C(=O)c3ccco3)=C(O)C(=O)N2Cc2ccccc2)ccc1O
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?