COc1cccc(COc2ccccc2C2Nc3ccc(Br)cc3C(=O)N2NC(=O)c2ccncc2)c1
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?