COc1ccc2[nH]c(CCNC(=O)c3cc([N+](=O)[O-])cc([N+](=O)[O-])c3)cc2c1
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?