O=C(C1=C(O)C(=O)N(Cc2cccnc2)C1c1cccc([N+](=O)[O-])c1)c1ccc2c(c1)OCO2
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?