Cc1ccc(C)c(Nc2c([N+](=O)[O-])cc(C(=O)N3CC(=O)Nc4ccccc43)cc2[N+](=O)[O-])c1
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?