COc1cc(/C=C2\SC(=S)N(C(Cc3ccccc3)C(=O)O)C2=O)ccc1O
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?