O=C1CCCc2oc3c(cc(NS(=O)(=O)c4ccc5c6c(cccc46)C(=O)N5)c4ccccc43)c21
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 pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?