COc1ccc(CCNC(=O)CCCn2c(=O)c3ccccc3n(CC(=O)Nc3c(C)cc(C)cc3C)c2=O)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?