O=C(NCCCN(CCCCN(CCCNC(=O)C(F)(F)F)Cc1ccccc1)Cc1ccccc1)C(F)(F)F
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?