COc1cc(/C=C2/C(=O)N(c3cccc(Br)c3)N=C2C)cc(OC)c1O
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?