COc1ccc(NC(=O)/C(C#N)=C/c2ncc([N+](=O)[O-])n2C)c(OC)c1
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?