Structures of dinitroazetidine and three of its carbonyl derivatives

The structures of DNAZ (3,3-dinitroazetidine), DNAZ-COH, DNAZ-CO-DNAZ, and (DNAZ-CO)(2) have been determined. DNAZ crystallizes in the space group P2( 1)/c with cell parameters a = 5.928(7) Angstrom, b = 15.8380(2) Angstrom, c = 12.6837(15) and beta = 93.23 degrees. DNAZ-COH crystallizes in the space group P2(1)/c with cell parameters a = 10.3270(10) Angstrom, b = 6.0615(12 ) Angstrom, c = 11.2514(12), and beta = 100.17 degrees. DNAZ-CO-DNAZ crysta llizes in the space group P2(1)/n with cell parameters a = 10.3630(6) Angst rom, b = 6.0901(5) Angstrom, c = 19.9421 (11) and beta = 102.74 degrees. (D NAZ-CO)(2) crystallizes in the orthorhombic, space group Fdd2 with cell par ameters a = 13.1956(10) Angstrom, b = 19.524(3) Angstrom, c = 10.3259(11). This last compound is unique in that the trans carbonyls are planar and the adjoining azetidine rings are also planar to within 0.1 degrees in all tor sion angles. DNAZ crystals have a dimeric asymmetric unit where two nonequa l molecules are bonded to each other with a single hydrogen bond. Like othe r four-membered rings with gem-dinitro groups, most of these dinitroazetidi nes display mutually perpendicular nitro groups.