O=C(O)c1ccc(N/N=C/C2=C(N3CCOCC3)/C(=C\c3ccccc3)CC2)cc1
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?