Using O=[N+]([O-])c1cc([N+](=O)[O-])c(O)c([N+](=O)[O-])c1O to produce O=[N+]([O-])c1cc([N+](=O)[O-])c([O-])c([N+](=O)[O-])c1[O-], please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.