O=C(Nc1cccc(C(F)(F)F)c1)C1Cc2c(-c3ccccc3Oc3ccccc3)ccnc2O1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?