CCCCNS(=O)(=O)c1ccc2nc(-c3cccnc3)cc(C(=O)NCCC)c2c1
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?