Hexazine

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Hexazine
Molecular formula N6
Molar mass 84.0402 g/mol
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Hexazine (also known as hexaazabenzene) is a hypothetical allotrope of nitrogen composed of 6 nitrogen atoms arranged in a ring-like structure analogous to that of benzene. It would be the final member of the azabenzene (azine) series, having all of the methylidyne groups of the benzene molecule replaced with nitrogen atoms. The two last members of this series, hexazine and pentazine, have not been observed, although many other members of the azine series have (such as pyridine, pyrimidine, pyrazine, and 1,3,5-triazine).

[edit] Stability

The hexazine molecule bears a structural similarity to the very stable benzene molecule. Like benzene, it has been calculated that hexazine is likely an aromatic molecule. Despite this, it has yet to be synthesized. In fact, it has been predicted computationally that the hexazine molecule is highly unstable. It has been suggested that this predicted instability is caused by the lone pairs on the nitrogen atoms, which may repel each other electrostatically and/or cause electron-donation to sigma antibonding orbitals.[1]

[edit] See also

[edit] References

  1. ^ Azabenzenes (azines) - The nitrogen derivatives of benzene with one to six N atoms
  • Jürgen Fabian and E. Lewars (2004). "Azabenzenes (azines) — The nitrogen derivatives of benzene with one to six N atoms: Stability, homodesmotic stabilization energy, electron distribution, and magnetic ring current; a computational study". Can. J. Chem. 82 (1): 50–69. doi:10.1139/v03-178. 
  • Paul Saxe and Henry F. Schaefer III (1983). "Cyclic D6h Hexaazabenzene-A Relative Minimum on the N6 Potential Energy Hypersurface?". J. Am. Chem. Soc. 105: 1760–1764. 
  • Hanspeter Huber (1982). "Is Hexazine Stable?". Angewandte Chemie International Edition in English 21 (1): 64–65. doi:10.1002/anie.198200641. 
  • M. N. Glukhovtsev  ; Paul von Ragué Schleyer (1992). "Structures, bonding and energies of N[6] isomers". Chemical Physics Letters 198 (6): 547–554. 
  • Ha, Tae-Kyu; Cimiraglia, R.; Nguyen, Minh Tho (1981). "Can hexazine (N6) be stable?". Chemical Physics Lette 83 (2): 317–319.