COc1ccc(/C(=N/O)c2ccccc2-c2nc3ccccc3c(=O)n2-c2ccc(S(=O)(=O)Nc3ncccn3)cc2)cc1C
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?