O=S(=O)(c1ccccc1Cl)N1CCCC(c2nc(O)c3nnn(Cc4ccc(OC(F)(F)F)cc4)c3n2)C1
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?