Cc1ccc(-c2[nH]nc3c2C(c2ccsc2)C(C#N)=C(N)O3)cc1
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?