Cc1ccc(NC(Nc2ccc(C)cc2C)=C(/C=C(\Cl)[N+](=O)[O-])[N+](=O)[O-])c(C)c1
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?