Using CI, O=[N+]([O-])c1cc(Br)cc2c1[nH]c1ccc(Br)cc12 to produce Cn1c2ccc(Br)cc2c2cc(Br)cc([N+](=O)[O-])c21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.