Using O=C1c2cccc(-c3nc4ccncc4[nH]3)c2-n2cccc21, NO to produce ON=C1c2cccc(-c3nc4ccncc4[nH]3)c2-n2cccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.