The crystal structure of 2,4,7-trinitro-9-fluorenone

D. L. Dorset, A. Hybl, H. L. Ammon
1972 Acta Crystallographica Section B  
The crystal structure of 2,4,7-trinitro-9-fluorenone, Cx3HsN307, has been determined. The crystals are monoclinic, space group P2t/n; cell dimensions are a=22.470 (3), b= 5.652 (1), c= 10.278 (2)/~, fl= 105-51 (I) °, Z=4; D"= 1.692 and Dx= 1.675 g.cm -3. An initial set of three-dimensional X-ray data was obtained using Cu radiation with a manually operated General-Electric diffractometer; a second set was measured using Mo radiation with a computer controlled Picker diffractometer. The
more » ... meter. The structure was solved with direct methods; refinement by full-matrix least-squares calculations gave an R index of 0.057 (weighted R= 0.045) for the Mo data. Anisotropic temperature factors were used for the carbon, nitrogen and oxygen atoms while the hydrogen atoms were refined with isotropic terms. The fluorene nucleus is planar. The bond lengths indicate that there is little interaction between the benzene rings, or between the rings and the carbonyl group. Because of steric crowding, the C(4) nitro group is twisted oUt of the C(1)-C(2)-C(3)-C(4)-C(4a)--C(9a) benzene ring plane by 34 °. A 23 ° r.m.s, rigid body libration of the C(7) nitro group about the C(7)-N bond was found. DOUGLAS L. DORSET, ALBERT HYBL' AND HERMAN L. AMMON 3123 C ( 5)~~C(6 ) 5 } ]~-,~H(6)
doi:10.1107/s0567740872007617 fatcat:ma6rlpjzbbdjpkvv2zf5axyt2q