Nitrogen pentahydride

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Nitrogen pentahydride

A possible structure of nitrogen pentahydride according to theory calculations[1]
Names
Other names
Ammonium hydride
Identifiers
3D model (
JSmol
)
  • [NH5]
  • [H-].[NH4+]
Properties
H5N
Molar mass 19.047 g·mol−1
Structure
Trigonal bipyramidal molecular geometry (covalent[1])
0 D (covalent[1])
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Nitrogen pentahydride, also known as ammonium hydride is a

solid rocket fuel for research in 1966.[6]

Research and attempts

Some studies believe that nitrogen pentahydride may exist in the formation of other metal atoms

crystal lattice, such as mercury[7][8] and lithium. There are also related studies to explore the possibility of a substitution reaction with ammonium halide.[9] There are also attempts to react ammonium and deuterium to produce the pentahydride, however some experiments show that it may only be a reactive intermediate, which will immediately decompose into ammonia and hydrogen,[10][1] and the same is true for experiments using deuterium.[2][1]
However, all the studies above are only theoretical calculations, the existence of nitrogen pentahydride has not been observed, and this substance has not been shown to exist.

An experimental attempted to do a

displacement reaction between ammonium trifluoroacetate and lithium hydride in the molten state, in order to study the possibility of the existence of nitrogen pentahydride:[10]

CF3COONH4 + LiH → CF3COOLi + [NH4H]

In the reaction between ammonium trifluoroacetate and lithium deuteride, the product ammonia contains 85% of ordinary ammonia and 15% of monodeuterated ammonia. The product hydrogen contains 66% of hydrogen deuteride, 21% of hydrogen gas and 13% of deuterium gas. In the product collected using tetradeuterated ammonium trifluoroacetate and lithium hydride, ammonia contains ND3, NHD2 and NH2D, while hydrogen contains 68% of hydrogen deuteride, 18% of hydrogen gas and 14% of deuterium gas. Therefore, it is speculated that the reaction may have two routes: one is to directly decompose into ammonia and hydrogen, the other is to first generate ammonium deuteride reactive intermediates, partly by forming deuterium anions and hydrogen cations to form deuterated hydrogen and ammonia and by the formation of hydride ions or deuterium cations to decompose into hydrogen or deuterium gas.[1]

But it immediately decomposed into hydrogen and ammonia, and it was impossible to prove its existence. Experiments with deuterium still get the same results:[2]

[NH4H] → NH3 + H2

Structure

Possible structures of covalently bounded nitrogen pentahydride[1]

Several papers have conducted theoretical calculations on nitrogen pentahydride, and believe that nitrogen pentahydride is unlikely to form ionic crystals of hydride and ammonium ions. However, it is possible that hydrogen is connected to one of the hydrogen atoms of ammonium.[1] It may also be similar to nitrogen pentafluoride, forming a three-center two-electron bond similar to carbonium ions, or those five hydrogen atoms are arranged in a triangular bipyramid structure around the nitrogen atom.[1]

Related compounds

A compound that is similar to nitrogen pentahydride is the theoretical

better source needed
]

References

  1. ^
    ISBN 9789814498548. Archived from the original
    on November 25, 2021.
  2. ^
    ISBN 9783662063330. Archived from the original on 2017-08-16.{{cite book}}: CS1 maint: multiple names: authors list (link
    )
  3. doi:10.1021/j100332a052.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  4. .
  5. .
  6. ^ Sterrett, K. F.; Caron, A. P. (1966). "High pressure chemistry of hydrogenous fuels". Northrop Space Labs. Archived from the original on 2011-08-23. Retrieved 2017-08-21.
  7. LCCN 2012945766. Archived from the original on 2017-08-16.{{cite book}}: CS1 maint: multiple names: authors list (link
    )
  8. .
  9. .
  10. ^ a b Olah, G. A,; Donovan, D. J.;Shen, J.; Klopman, G.(J. Am. Chem. Soc. 97 [1975] 3559/61).
  11. .
  12. from the original on 2015-02-12.
  13. ^ ^ A Guide to Organophosphorus Chemistry Louis D. Quin 2000 John Wiley & Sons ISBN 0-471-31824-8
  14. ^ "arsorane". CHEBI. Archived from the original on 2017-08-21. Retrieved 2017-08-21.