CCc1ccc(Nc2n[n+](-c3ccccc3)c(-c3ccc(OC)c(Br)c3)s2)cc1.[Cl-]
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?