NC(=O)[C@@H]1CC2(CC(c3cccc(NC(=O)CC(c4ccccc4)c4ccccc4)c3)=NO2)CN1C(=O)[C@@H]1CCC(=O)N1
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?