N=C1/C(=C\c2ccc(-c3cccc(C(=O)O)c3)o2)C(=O)N=C2SC=C(c3ccccc3)N12
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?