NCCCC[C@@H]1NC(=O)c2cc([N+](=O)[O-])cc(I)c2SC[C@@H](C(=O)NCC(N)=O)NC(=O)CNC1=O
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?