COc1ccccc1NS(=O)(=O)c1cccc(C(=O)NCC(c2ccco2)N2CCCC2)c1
The negative base-10 logarithmic of dissociation constant (pKa) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?