COc1ccc(C(=O)NCc2nnc(SCC(=O)Nc3ccccc3)n2-c2ccccc2)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?