O=[N+]([O-])c1ccccc1/C=C/C=N/n1c(S)nnc1-c1cc(-c2ccccc2)[nH]n1
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?