COc1ccc(C(=O)NCC(=O)N=Nc2c(O)n(Cc3ccccc3)c3ccccc23)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?