COc1ccc(C(=O)NCCn2cc(SCC(=O)Nc3ccc4c(c3)OCCO4)c3ccccc32)cc1OC
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?