4,5-Dihydro-2,7-dinitropyrene , with CAS number of 117929-12-1, can be called pyrene, 4,5-dihydro-2,7-dinitro- ; 4,5-Dihydro-2,7-dinitropyrene ; 2,7-Dinitro-4,5-dihydro-pyrene ; 2,7-Dinitro-4,5-dihydropyrene .