Cc1sc2nc(CSc3nnc(Cc4cccs4)n3C3CCCCC3)nc(O)c2c1C
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?