Cc1nc(/N=N\c2ccc(S(=O)(=O)O)cc2S(=O)(=O)O)c(COP(=O)(O)O)c(C=O)c1O
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?