COc1cccc(-c2nn(C)c3sc(C(=O)Nc4ccc5c(c4)OCCO5)cc23)c1
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?