1H-pyrrolo[2,3-b]pyridine, 4-nitro- 4-nitro-1H-pyrrolo[2,3-b]pyridine InChI=1/C7H5N3O2/c11-10(12)6-2-4-9-7-5(6)1-3-8-7/h1-4H,(H,8,9