O=c1[nH]c(=O)n(Cc2ccco2)c2c1C(C(F)(F)F)(C(F)(F)F)NC(C1CCCCC1)=N2
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?