O=C(C1CCCN(S(=O)(=O)c2c[nH]cn2)C1)N(CCc1ccccc1)Cc1ccccc1
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?