O=C(N/N=C/c1sc(N2CCOCC2)nc1-c1ccccc1)c1cccc(S(=O)(=O)N2CCCC2)c1
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?