O=C(c1ccccc1-c1ncc[nH]1)N1CCCC(Nc2ccc(F)cc2)C1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?