O=S(=O)(NC1=NCCC1)c1cccc(N=C(S)Nc2ccc(OC(F)F)cc2)c1
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 negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?