Conformation of overloaded aromatic nitrocompounds

Dashevskii, V. G.; Struchkov, Yu. T.; Akopyan, Z. A.

doi:10.1007/bf00743552

Cited by 11 publications

(8 citation statements)

References 15 publications

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“…The twist angles for the C(2) and C(7) nitro groups are respectively 3.7 and 15.3 ° and are comparable with the angles found in 2,4,7-trinitro-9-dicyanomethylene [C(2)-NO2 = C(7)-NO2 = 7"8 °] and 2,7-dinitro-9-dicyanomethylene fluorene [C(2)-NO2=C(7)-NO2= 17"6°]. Dashevskii, Struchkov & Akopyan (1966) have reported that an out-of-plane NO2 rotation of 18 ° requires only 0.6 kcal.mole -1, a value within the range of available thermal energy. The C(4)-NO2 moiety, however, is appreciably more crowded than the other two NO2's; the 32.7 ° C-N twist represents a stress energy of ca.…”

Section: Introductionsupporting

confidence: 75%

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

Dorset¹,

Hybl²,

Ammon³

1972

Acta Crystallogr Sect B

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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 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.

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Section: Introductionsupporting

confidence: 75%

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

Dorset¹,

Hybl²,

Ammon³

1972

Acta Crystallogr Sect B

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“…The values of ANGLE for the three Br compounds are 2, 16 and 37 °. Dashevskii, Struchkov & Akopyan (1966) calculated the values for ANGLE for a number of orthohalonitrobenzenes: 20.2, 26.0 and 34.5 ° for C1, Br and I, respectively. These different values compared with the crystal structures are not only to be explained in terms of the absence of packing forces but possibly also by the…”

Section: Halogen Atomsmentioning

confidence: 99%

“…• (1) • (4) absence of other substituents on the ring in the study of Dashevskii, Struchkov & Akopyan (1966).…”

Section: Halogen Atomsmentioning

confidence: 99%

The influence of ortho substituents on the twisting angle of a nitro group with respect to aromatic six-membered carbon rings

Ridder¹,

Schenk²

1995

Acta Crystallogr Sect B

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“…Such a resonance inhibition is common in polysubstituted nitrobenzene derivatives (e.g. 1,2,4,5-tetrachloro-3,6-dinitrobenzene; Wigand et al, 1987) and is not surprising, as it has been shown that the energy required for tilting a nitro group out of a benzene plane is rather low (Dashevskii et al, 1966). In polymorph I, the dihedral angle between the nitro and benzene mean planes is 85.60 (10) for the centrosymmetric molecule and 79.76 (8) in the other molecule.…”

Section: Figurementioning

confidence: 94%

Dimorphic forms of 3,6-dinitrodurene in a single space group

Aguilar

Bernès²

2009

Acta Crystallogr C

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3,6-Dinitrodurene (1,2,4,5-tetramethyl-3,6-dinitrobenzene), C(10)H(12)N(2)O(4), has been crystallized in two polymorphic forms which may be distinguished by their colours in the solid state. Polymorph I gives clear colourless prismatic crystals, while polymorph II crystallizes in the dark and under an inert atmosphere as irregular purple blocks. Both forms belong to the space group C2/c, with both asymmetric units containing two half-molecules. One molecule is located on an inversion centre and the other lies on a twofold axis. The polymorphism arises from different orientations of the twofold axis: in form I, this axis passes through the mid-points of two C-C bonds of the benzene ring and, as a consequence, all atoms in the asymmetric unit are in general positions. In form II, the N atoms of the nitro groups and the C(ipso) atoms are located on the binary axis. Comparing phases I and II, slightly different conformations are observed for the nitro substituents, while the stacking structures are very similar.

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Conformation of overloaded aromatic nitrocompounds

Cited by 11 publications

References 15 publications

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

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

The influence of ortho substituents on the twisting angle of a nitro group with respect to aromatic six-membered carbon rings

Dimorphic forms of 3,6-dinitrodurene in a single space group

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