O=C(NC1CCN(Cc2ccccc2)CC1)c1cc2nc(-c3ccc(Cl)s3)cc(C(F)(F)F)n2n1
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 negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?