O=C(Nc1cccc(-c2nn3ccccc3c2-c2ccnc(Nc3ccc4c(c3)CNCC4)n2)c1)c1c(F)cccc1F
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?