O=C(NCCCN1CCOCC1)c1ccc2c(=O)n(-c3ccc(F)c(Cl)c3)c(=S)[nH]c2c1
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 pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?