O=S(=O)([O-])CCC[n+]1c(/C=C\Nc2ccccc2)oc2ccc(-c3ccccc3)cc21
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?