O=C1C2C(C(=O)N1c1ccccc1)C1([N+](=O)[O-])C=C3c4ccccc4N(C(=O)c4ccccc4)C32C2C(=O)N(c3ccccc3)C(=O)C21
A lower number of negative pKa indicates that the acid dissociates more entirely in water. What is the negative pKa of this molecule?