COc1ccccc1N1C(=O)C2C(C(=O)c3ccccc3)=NN(c3ccc(Br)cc3)C2C1=O
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?