O=[N+]([O-])/C(C(Cl)=C(Cl)Cl)=C(\Nc1cccc2ccccc12)Sc1ccccc1
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?