O=C(OCCNc1ccc(C(F)(F)F)cc1[N+](=O)[O-])c1cc2ccccc2oc1=O
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?