AndersHoveland
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Allotropes of Nitrogen
At least three different allotropes of elemental nitrogen exist, the latter two do not contain the N-N triple bond, suggesting that
they might be energetic.
http://pubs.acs.org/cen/news/8231/8231notw6.html
Solid nitrogen was still stable after the pressure was reduced to normal, but only when liquid nitrogen was used to maintain a low temperature.
"An allotropic form of nitrogen was synthesized directly from molecular nitrogen at temperatures exceeding 2500K and pressures above 110 GPa [Eremets,
Gavriliuk et al., 2004]. This phase can be quenched to ambient pressure due to the large hysteresis of the material, but only at low temperatures,
precluding performance testing of the material [Eremets, Gavriliuk et al., 2004]."
There is also a "black phase" of solid nitrogen, which is stable at room temperature, but only under extreme pressure, or alternatively, stable at
ambient pressure, but only when cryogenic temperatures are maintained.
" a new, dark, apparently non-molecular phase has been recently found above 180 GPa at 80 K [3] and then at room and elevated temperatures. Some
properties of this black phase are close to that predicted for the polymeric nitrogen; that is, the value equilibrium pressure (about 100 GPa), and a
huge hysteresis enabling the black phase to be recovered at ambient pressure and low temperatures."
Apparently this solid polymeric forms of nitrogen.
A.F. Goncharov et al Phys. Rev. Lett. 85, 1262*1265 (2000);
E. Gregoryanz et al Phys. Rev. B 64, 052103 (2001), 224108 (2002).
These are completely different from plain solid nitrogen, still composed of individual N2 molecules, which freezes at -210.01 degC. The solid has a
density of 1.026 g/cm3 at -252 deg C.
These allotropes described above are unrelated to the "all-nitrogen salts" that researchers have been trying to synthesize [pentazenium pentazolate,
N5N5]. It has been calculated that such an ionic allotrope of nitrogen would be 2-3 times more energetic than RDX.
Does anyone know whether these other allotropes of nitrogen that have already been created are explosive? Obviously they would only be explosive not
under immense pressure (so they would have to be continually cooled by liquid nitrogen to remain stable). Likely the quantities of substance yet
produced has been too small to accurately test. How energetic do you think these allotropes would be?
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AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
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Scientists at the Carnegie Institution of Washington reported they have transformed nitrogen, normally a transparent gas, into an opaque solid by
subjecting the gas to immense pressure.
Russell Hemley, Mikhail Eremets, Ho-kwang Mao and Eugene Gregoryanz performed the research at Carnegie's Geophysical Laboratory. They used pressures
of up to 2.4 million times the atmospheric pressure at sea level to create the solid nitrogen, which can remain stable even when the pressure
returns to normal.
Team leader Hemley described the results as a "major breakthrough." For years, theorists have predicted that molecular nitrogen would become either a
semiconductor or a metal if subjected to pressures on the order of a million atmospheres.
Previous experiments have been limited in the amount of pressure that could be applied to nitrogen, and in the number of measurements that could be
performed on the material while under pressure. In this experiment, the researchers used newly developed techniques that allowed them to measure
electrical conductivity at very high pressures and various temperatures.
Physicist Chi-Chang Kao, of the Brookhaven National Laboratory, termed the breakthrough "quite important. The triple bond in the nitrogen
molecule is extremely strong. The Carnegie group has shown that you can break this bond in a laboratory setting for the
first time ever."
Kao told United Press International visible light can pass through gaseous nitrogen but not the more opaque, solid nitrogen formed by the Carnegie
team. In its solid state, nitrogen has available electrons that provide its semi-conducting properties.
Kao told UPI from Upton, Long Island, "It does store a large amount of energy and may have some military use -- perhaps some sort of new bomb."
"Such a dense form of solid nitrogen would reconfigure to its gaseous state very quickly," Lattman said. "In the process, it would release a
tremendous amount of energy and under the right conditions, could be used as an explosive. It would have to be kept at a very low
temperature, I would think, to remain solid at ambient pressures. Raising the temperature much would definitely create explosive conditions."
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http://www.xent.com/FoRK-archive/jan99/0474.html
http://en.wikipedia.org/wiki/Octaazacubane
https://www.llnl.gov/str/June01/Manaa.html
[Edited on 8-12-2011 by AndersHoveland]
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