S=C(N/N=C(/c1ccccc1)c1ccccn1)N(Cc1ccccn1)Cc1ccccn1
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?