6,6,8-Trinitropentacyclo[5.3.0.02,5.03,9.04,8]decane, C10H9N3O6

Abstract

The molecule is substantially distorted from a cubane geometry; two of the six sides of the framework are four-membered rings and four sides are five-membered rings. The average C-C-C angles in the four-and five-membered rings are 89.2 and 102.9 °, respectively. C-C bond lengths show the effects of the nitro substituents: the average of the two bonds linked to C(NO2) 2 is 1.507 (4)/k, and the three bonds joined to C(NO 2) average 1.560 (4)/k. Introduction.There is considerable interest in the synthesis and chemistry of strained energetic compounds (e.g. Sollott & Gilbert, 1980; Eaton, Ravi Shankar, Price, Pluth, Gilbert, Alster & Sandus, 1984; Marchand & Suri, 1984). Polynitropolycyclic compounds are potential members of this important class.In this paper, we report the structure of the first polynitrobishomocubane (I) to have been prepared *Mailing address: National Bureau of Standards, Reactor Radiation Division, Gaithersburg, MD 20899, USA. (Marchand & Suri, 1984). The structure of one other homocubane (homocubanecarboxylic acid p-bromoanilide; Pettersen, 1967) has been reported; these structural data, however, are not readily available.Experimental. Six-sided parallelepiped crystal, 0.49 x 0.23 x0.19mm, from ethyl acetate-hexane; cell parameters determined and intensity measurements made with a Picker FACS-I diffractometer, graphite monochromator, Cu radiation; unit-cell parameters determined by least squares from 20 values of 14 reflections automatically centered at +20; intensities measured with 0-20 scan technique, 2 ° min -I 20 scan speed, 10s backgrounds, 20 scan width = 1.6 ° + 0.3 ° tan0; four standards monitored at 100 reflection intervals, maximum intensity variation <2%; 20 maximum of 126 °, h,k,l range 0-10, 0-8, -18-18; 2111 total reflections measured, 1901 unique (excluding systematic absences), 1495 3a above background; Gaussian quadrature (8 x 8 × 8 grid) absorption correction (Amax/Aml,= 1.558/1"234); structure solved With MULTAN80 (Main, Fiske, Hull, Lessinger, Germain, Declercq & Woolfson, 1980); H atoms located in difference map; full-matrix least-squares structure refinement minimized ~W (Fo--Fc) c (1) C(2) C(3) C(4) C(5) C (6) Discussion. Atomic coordinates and temperature fac-c(7) c(8) tors for C, N, O, and H are listed in Table 1;* an c(9) OR TEP (Johnson, 1971) drawing is shown in Fig. 1. c(l 0)The C-C bond lengths fall into two groups: the four N(2) bonds involved with bridging atoms C(9) and C (10) N (3) o(1) range from 1.505 (4) to 1.525 (4)A and average 0(2) 1.513(4)/k; the cubane-skeleton bonds range from 0(3) 1.526 (5) to 1.570 (4) A and average 1.550 (4) A. In 0(4) cubane (Fleischer, 1964) and 1,4-dinitrocubane (Eaton 0(5) 0 (6) et al., 1984) the average C-C distances are 1.551 (3) H(1) and 1.558(3)A, respectively. The C-C-C bond H (2) H (3) angles in the two four-membered rings range from H(4) 85.6 (2) to 92.8 (2) ° and average 89.2 (2) °. In the four H (5) H (6) five-membered rings, the endocyclic angles opposite the rt (7) bridging atoms C(9) and C(10) average 102....

Structure of 6,6,10,10-tetranitropentacyclo[5.3.0.02,5.03,9.04,8]decane, C10H8N4O8

“…In trinitrobishomocubane (Ammon et al, 1985) the corresponding averages are 1.513 and 1.550A, while in cubane (Fleischer, 1964) the average C-C distance is 1.551 A. For those geometric parameters which are equivalent, trinitrobishomocubane and tetranitrobishomocubane are nearly isostructural.…”

“…The title compound, a tetranitrobishomocubane (TNBHC), was prepared as part of a program to synthesize strained energetic compounds (Marchand & Reddy, 1984). The structure (Ammon, Zhang, Choi, Sandus, Marchand & Suri, 1985) and synthesis of a trinitrobishomocubane have been reported previously (Marchand & Suri, 1984). The structure of this compound was investigated as part of a continuing study of the structural parameters of energetic substituents in polycyclic nitro compounds.…”