N=C1/C(=C/c2ccc(O)cc2)C(=O)N=C2SC(CC(=O)N3CCCC3)=NN12
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?