O=C(NC1CCCc2c1cnn2-c1ccccc1F)c1cc(-c2ccccc2)n[nH]1
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?