NC(=O)/C(=N\NC(=O)C[n+]1ccccc1)C1NC(=O)NC1=O.[Cl-]
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?