CC1(Br)C(=O)NC(=O)N(C2CC(N=[N+]=[N-])C(CO)O2)C1N=[N+]=[N-]
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?