COc1ccc(C[C@@H]2CN(C(=O)c3ccccc3)[C@H](Cc3ccc(O)cc3)CN2C(=O)c2ccccc2)cc1Br
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?