COc1ccc(N2CCN(c3nc4ccccc4nc3NS(=O)(=O)c3ccccc3)CC2)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?