O=C(CCNS(=O)(=O)c1ccccc1F)N1CCN(S(=O)(=O)c2cccc(F)c2)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?