COc1ccc(-n2c3c(cc(C(=O)NNc4ccccc4)c2=O)C(=O)CC(C)(C)C3)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?