COc1ccccc1N1CCN(C2CC(=O)N(c3cccc(Br)c3)C2=O)CC1
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?