CN(CCN)[C@H](CSSC[C@@H](c1ccccc1O)N(C)CCN)c1ccccc1O
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?