COc1ccc2[nH]c(Sc3c([N+](=O)[O-])nc(C)n3Cc3ccccc3)nc2c1
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?