O=c1nc2n(c(O)c1C(c1ccc(F)cc1)c1c(O)nc3n(c1=O)CCCS3)CCCS2
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?