Cc1ccccc1C(=O)N1CCN(c2ccc(NC(=S)NC(=O)c3cccs3)cc2)CC1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?