COc1cc(/C=C2/C(=O)NN(c3ccccc3)C2=O)cc(Br)c1O
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?