C/C(=N/NC(=S)Nc1ccc([N+](=O)[O-])cc1)c1cccc(/C(C)=N\NC(=S)Nc2ccc([N+](=O)[O-])cc2)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 pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?