View source for Chemistry:Inorganic imide

The inorganic '''imides''' are compounds containing an ion composed of [[Chemistry:Nitrogen|nitrogen]] bonded to [[Chemistry:Hydrogen|hydrogen]] with formula HN<sup>2−</sup>. Organic [[Chemistry:Imide|imide]]s have the NH group, and two single or one double covalent bond to other atoms. The imides are related to the inorganic amides (H<sub>2</sub>N<sup>−</sup>), the [[Chemistry:Nitride|nitride]]s (N<sup>3−</sup>) and the nitridohydrides (N<sup>3−</sup>•H<sup>−</sup>).
In addition to solid state imides, molecular imides are also known in dilute gases, where their spectrum can be studied.

When covalently bound to a metal, an imide [[Chemistry:Ligand|ligand]] produces a [[Chemistry:Transition metal imido complex|transition metal imido complex]].  

When the hydrogen of the imide group is substituted by an organic group, an organoimide results. Complexes of [[Chemistry:Actinide|actinide]] and rare earth elements with organoimides are known.<ref>{{cite journal |last1=Schädle |first1=Dorothea |last2=Anwander |first2=Reiner |title=Rare-earth metal and actinide organoimide chemistry |journal=Chemical Society Reviews |date=2019 |volume=48 |issue=24 |pages=5752–5805 |doi=10.1039/c8cs00932e|pmid=31720564 |s2cid=207938163 }}</ref>

==Properties==
[[Chemistry:Lithium imide|Lithium imide]] undergoes a phase transition at 87&nbsp;°C where it goes from an ordered to a more symmetric disordered state.<ref name=":0">{{Cite thesis|title=Structural and thermogravimetric studies of alkali metal amides and imides|url=https://ora.ox.ac.uk/objects/uuid:df7b324d-c33d-4265-91cb-0555c3a10bec|publisher=Oxford University, UK|date=1999|degree=PhD|language=en|first=Rebecca L.|last=Lowton}}</ref>

==Structure==
Many imides have a cubic rock salt structure, with the metal and nitrogen occupying the main positions. The position of the hydrogen atom is hard to determine, but is disordered.

Many of the heavy metal simple imide molecules are linear. This is due to the filled 2p orbital of nitrogen donating electrons to an empty d orbital on the metal.<ref name=":4">{{Cite journal|last1=Janczyk|first1=Alexandra|last2=Lichtenberger|first2=Dennis L.|last3=Ziurys|first3=Lucy M.|date=February 2006|title=Competition between Metal-Amido and Metal-Imido Chemistries in the Alkaline Earth Series: An Experimental and Theoretical Study of BaNH|url=https://pubs.acs.org/doi/10.1021/ja053473k|journal=Journal of the American Chemical Society|language=en|volume=128|issue=4|pages=1109–1118|doi=10.1021/ja053473k|pmid=16433526|issn=0002-7863}}</ref>

==Formation==
Heating [[Chemistry:Lithium amide|lithium amide]] with [[Chemistry:Lithium hydride|lithium hydride]] yields lithium imide and hydrogen gas. This reaction takes place as released [[Chemistry:Ammonia|ammonia]] reacts with lithium hydride.<ref name=":0" />

Heating magnesium amide to about 400&nbsp;°C yields magnesium imide with the loss of [[Chemistry:Ammonia|ammonia]]. Magnesium imide itself decomposes if heated between 455 and 490&nbsp;°C.<ref name=dol/>

Beryllium imide forms from beryllium amide when heated to 230&nbsp;°C in a vacuum.<ref name=":6">{{Cite journal|last1=Jacobs|first1=Herbert|last2=Juza|first2=Robert|date=November 1969|title=Darstellung und Eigenschaften von Berylliumamid und -imid|url=http://doi.wiley.com/10.1002/zaac.19693700507|journal=Zeitschrift für anorganische und allgemeine Chemie|language=de|volume=370|issue=5–6|pages=248–253|doi=10.1002/zaac.19693700507|issn=0044-2313}}</ref>

When strontium metal is heated with ammonia at 750&nbsp;°C, the dark yellow strontium imide forms.<ref name=":1" />

When barium vapour is heated with ammonia in an electrical discharge, the gaseous, molecular BaNH is formed.<ref>{{cite journal |last1=Janczyk |first1=Alexandra |last2=Lichtenberger |first2=Dennis L. |last3=Ziurys |first3=Lucy M.|title=Competition between Metal-Amido and Metal-Imido Chemistries in the Alkaline Earth Series: An Experimental and Theoretical Study of BaNH |journal=Journal of the American Chemical Society |date=February 2006 |volume=128 |issue=4 |pages=1109–1118 |doi=10.1021/ja053473k|pmid=16433526 }}</ref> Molecules ScNH, YNH, and LaNH are also known.<ref name=":2">{{cite journal |last1=Bhattacharyya |first1=Soumen |last2=Harrison |first2=James F. |title=Electronic structure and bonding of the ScNH and YNH molecules |journal=Chemical Physics Letters |date=September 2020 |volume=754 |pages=137735 |doi=10.1016/j.cplett.2020.137735|bibcode=2020CPL...75437735B |s2cid=225222419 }}</ref><ref name=":3">{{cite journal |last1=Bhattacharyya |first1=Soumen |last2=Harrison |first2=J. F. |title=Theoretical study of the electronic structure and bonding of LaNH |journal=Chemical Physics Letters |date=1 September 2019 |volume=730 |pages=551–556 |doi=10.1016/j.cplett.2019.06.042|bibcode=2019CPL...730..551B |s2cid=197120516 }}</ref>

==Hydrogen storage==
Inorganic imides are of interest because they can reversibly store hydrogen, which may be important for the [[Physics:Hydrogen economy|hydrogen economy]]. For example, calcium imide can store 2.1% mass of hydrogen. Li<sub>2</sub>Ca(NH)<sub>2</sub> reversibly stores hydrogen and release it at temperatures between 140 and 206&nbsp;°C. It can reversibly hold 2.3% hydrogen.<ref name=verb>{{cite thesis |last1=Verbraeken |first1=Maarten Christiaan |title=Doped Alkaline Earth (nitride) Hydrides |date=February 2009 |publisher=University of St Andrews |url=https://research-repository.st-andrews.ac.uk/handle/10023/714|page=19|hdl=10023/714 }}</ref> When hydrogen is added to the imide, amides and hydrides are produced. When imides are heated, they can yield hydridonitrides or nitrides, but these may not easily reabsorb hydrogen.

==List==
===Ionic===
{|class="wikitable"
!name
!formula
!structure
!space group
!unit cell
!references
|-
|[[Chemistry:Lithium imide|Lithium imide]]
|Li<sub>2</sub>NH
|cubic
|''Fm''{{overbar|3}}''m''
|a=5.0742
|<ref name=":0" />
|-
|Beryllium imide
|BeNH
|
|
|
|<ref name=":6" />
|-
|Magnesium imide
|MgNH
|hexagonal
|''P''6/''m''
|a = 11.567 Å c = 3.683Å Z=12
|<ref name=dol>{{cite journal |last1=Dolci |first1=Francesco |last2=Napolitano |first2=Emilio |last3=Weidner |first3=Eveline |last4=Enzo |first4=Stefano |last5=Moretto |first5=Pietro |last6=Brunelli |first6=Michela |last7=Hansen |first7=Thomas |last8=Fichtner |first8=Maximilian |last9=Lohstroh |first9=Wiebke |title=Magnesium Imide: Synthesis and Structure Determination of an Unconventional Alkaline Earth Imide from Decomposition of Magnesium Amide |journal=Inorganic Chemistry |date=7 February 2011 |volume=50 |issue=3 |pages=1116–1122 |doi=10.1021/ic1023778|pmid=21190329 |url=https://d1wqtxts1xzle7.cloudfront.net/43709303/IC_11_Dolci.pdf?1457950512=&response-content-disposition=inline%3B+filename%3DMagnesium_Imide_Synthesis_and_Structure.pdf}}</ref>
|-
|Lithium magnesium imide
|Li<sub>2</sub>Mg(NH)<sub>2</sub>
|
|
|
|<ref name=verb/>
|-
|
|Si<sub>2</sub>N<sub>2</sub>(NH)
|
|
|
|<ref name=":8">{{Cite journal|last1=Peters|first1=D.|last2=Paulus|first2=E. F.|last3=Jacobs|first3=H.|date=1990|title=Darstellung und Kristallstruktur eines Kaliumimidonitridosilicats, K3Si6N5(NH)6|url=http://doi.wiley.com/10.1002/zaac.19905840112|journal=Zeitschrift für anorganische und allgemeine Chemie|language=de|volume=584|issue=1|pages=129–137|doi=10.1002/zaac.19905840112|issn=0044-2313}}</ref>
|-
|
|K<sub>2</sub>Si(NH)<sub>3</sub>
|amourphous
|
|
|<ref name=":9">{{Cite journal|last=Ali|first=S. I.|date=December 1970|title=Reactions of Silicon Tetrabromide and -iodide with Potassium Amide in liquid ammonia|url=http://doi.wiley.com/10.1002/zaac.19703790112|journal=Zeitschrift für anorganische und allgemeine Chemie|language=de|volume=379|issue=1|pages=68–71|doi=10.1002/zaac.19703790112|issn=0044-2313}}</ref>
|-
|
|K<sub>2</sub>Si<sub>2</sub>(NH)<sub>5</sub>
|amourphous
|
|
|<ref name=":9" />
|-
|
|K<sub>2</sub>Si<sub>3</sub>(NH)<sub>7</sub>
|amourphous
|
|
|<ref name=":9" />
|-
|potassium imido nitrido silicate
|K<sub>3</sub>Si<sub>6</sub>N<sub>5</sub>(NH)<sub>6</sub>
|cubic
|P4<sub>3</sub>32
|a = 10.789
|<ref name=":8" />
|-
|Calcium imide 
|CaNH
|hexagonal
|''Fm''3''m''
|
|<ref name="verb" />
|-
|Lithium calcium imide
|Li<sub>2</sub>Ca(NH)<sub>2</sub>
|hexagonal
|
|
|<ref name=verb/>
|-
|Magnesium calcium diimide
|MgCa(NH)<sub>2</sub>
|cubic
|
|
|<ref>{{cite journal |last1=Liu |first1=Yongfeng |last2=Liu |first2=Tao |last3=Xiong |first3=Zhitao |last4=Hu |first4=Jianjiang |last5=Wu |first5=Guotao |last6=Chen |first6=Ping |last7=Wee |first7=Andrew T. S. |last8=Yang |first8=Ping |last9=Murata |first9=Kenji |last10=Sakata |first10=Ko |title=Synthesis and Structural Characterization of a New Alkaline Earth Imide: MgCa(NH)2 |journal=European Journal of Inorganic Chemistry |date=November 2006 |volume=2006 |issue=21 |pages=4368–4373 |doi=10.1002/ejic.200600492|doi-access=free }}</ref>
|-
|Lithium calcium magnesium imide
|Li<sub>4</sub>CaMg(NH)<sub>4</sub>
|
|
|
|<ref name=verb/>
|-
|Strontium imide
|SrNH
|orthorhombic
|''Pmna''
|a =7.5770 b =3.92260 c =5.69652 Z=4
|<ref name=":1">{{cite journal |last1=Schultz‐Coulon |first1=Verena |last2=Irran |first2=Elisabeth |last3=Putz |first3=Bernd |last4=Schnick |first4=Wolfgang |title=β-SrNH und β-SrND – Synthese und Kristallstrukturbestimmung mittels Röntgen- und Neutronenbeugung an Pulvern |journal=Zeitschrift für anorganische und allgemeine Chemie |date=1999 |volume=625 |issue=7 |pages=1086–1092 |doi=10.1002/(SICI)1521-3749(199907)625:7<1086::AID-ZAAC1086>3.0.CO;2-B}}</ref>
|-
|Tin amide imide
|Sn(NH<sub>2</sub>)<sub>2</sub>NH
|
|
|
|<ref>{{Cite journal|last1=Watney|first1=Nicholas S. P.|last2=Gál|first2=Zoltán A.|last3=Webster|first3=Matthew D. S.|last4=Clarke|first4=Simon J.|date=2005|title=The first ternary tin(ii) nitride: NaSnN|url=http://xlink.rsc.org/?DOI=b505208d|journal=Chemical Communications|language=en|issue=33|pages=4190–2|doi=10.1039/b505208d|pmid=16100599|issn=1359-7345}}</ref><ref>{{Cite journal|last=Maya|first=Leon|date=May 1992|title=Preparation of tin nitride via an amide-imide intermediate|url=https://pubs.acs.org/doi/abs/10.1021/ic00036a044|journal=Inorganic Chemistry|language=en|volume=31|issue=10|pages=1958–1960|doi=10.1021/ic00036a044|issn=0020-1669}}</ref>
|-
|Barium imide
|BaNH
|tetragonal
|''I''4/''mmm''
|a=4.062 c=6.072 Z=2
|<ref>{{cite journal |last1=Wegner |first1=B. |last2=Essmann |first2=R. |last3=Jacobs |first3=H. |last4=Fischer |first4=P. |title=Synthesis of barium imide from the elements and orientational disorder of anions in BaND studied by neutron diffraction from 8 to 294 K |journal=Journal of the Less Common Metals |date=December 1990 |volume=167 |issue=1 |pages=81–90 |doi=10.1016/0022-5088(90)90291-Q |language=en}}</ref>
|-
|Lanthanum imide
|La<sub>2</sub>(NH)<sub>3</sub>
|rock salt
|
|a=5.32
|<ref>{{Cite journal|last1=Jacobs|first1=H|last2=Gieger|first2=B|last3=Hadenfeldt|first3=C|date=March 1979|title=Über das system kalium/lanthan/ammoniak|url=https://linkinghub.elsevier.com/retrieve/pii/002250887990136X|journal=Journal of the Less Common Metals|language=de|volume=64|issue=1|pages=91–99|doi=10.1016/0022-5088(79)90136-X}}</ref>
|-
|Cerium imide
|CeNH
|
|
|
|<ref>{{Cite journal|last1=Imamura|first1=Hayao|last2=Kawasoe|first2=Masahiro|last3=Imayoshi|first3=Kyouya|last4=Sakata|first4=Yoshihisa|date=2015|title=Preparation and Some Properties of Nanostructural Rare Earth Nitrides by Using the Reaction of Hydrides with Ammonia|url=http://ijtan.avestia.com/2015/001.html|journal=International Journal of Theoretical and Applied Nanotechnology|volume=3|pages=1–8|doi=10.11159/ijtan.2015.001|doi-access=free}}</ref>
|-
|Ytterbium imide
|YbNH
|cubic
|
|a=4.85
|<ref>{{Citation|last=Imamura|first=Hayao|title=The Role of Rare Earths in Catalysis|chapter=Chapter 182 The metals and alloys (prepared utilizing liquid ammonia solutions) in catalysis II|date=2000|chapter-url=https://linkinghub.elsevier.com/retrieve/pii/S0168127300290053|series=Handbook on the Physics and Chemistry of Rare Earths|volume=29|pages=45–74|publisher=Elsevier|language=en|doi=10.1016/s0168-1273(00)29005-3|isbn=978-0-444-50472-2|access-date=2020-11-10}}</ref>
|-
|
|NH<sub>4</sub>[Hg<sub>3</sub>(NH)<sub>2</sub>](NO<sub>3</sub>)<sub>3</sub>
|cubic
|''P''4<sub>1</sub>32
|a = 10.304, Z = 4
|<ref>{{Cite journal |title= Bildung von NH4&#91;Hg3(NH)2&#93;(NO3)3 und Umwandlung in &#91;Hg2N&#93;(NO3)|journal= Zeitschrift für Anorganische und Allgemeine Chemie|year= 2002|doi=10.1002/1521-3749(200212)628:12<2709::AID-ZAAC2709>3.0.CO;2-P|last1= Nockemann|first1= Peter|last2= Meyer|first2= Gerd|volume= 628|issue= 12|pages= 2709–2714}}</ref>
|-
|Thorium nitride imide
|Th<sub>2</sub>N<sub>2</sub>(NH)
|hexagonal
|''P''3''m''{{overbar|1}}
|''a'' = 3.886 c = 6.185 Å
|<ref>{{Cite journal|last1=Silva|first1=G. W. Chinthaka|last2=Yeamans|first2=Charles B.|last3=Weck|first3=Philppe F.|last4=Hunn|first4=John D.|last5=Cerefice|first5=Gary S.|last6=Sattelberger|first6=Alfred P.|last7=Czerwinski|first7=Ken R.|date=2012-03-05|title=Synthesis and Characterization of Th 2 N 2 (NH) Isomorphous to Th 2 N 3|url=https://pubs.acs.org/doi/10.1021/ic300025b|journal=Inorganic Chemistry|language=en|volume=51|issue=5|pages=3332–3340|doi=10.1021/ic300025b|pmid=22360445|issn=0020-1669}}</ref>
|}

===Molecular===
{| class="wikitable"
!name
!formula
!structure
!symmetry
!CAS
!references
|-
|
|B<sub>2</sub>(NH)<sub>3</sub>
|polymer
|
|
|<ref name=":7">{{Cite journal|last1=Janik|first1=Jerzy F.|last2=Wells|first2=Richard L.|date=January 1996|title=Gallium Imide, {Ga(NH) 3/2 } n , a New Polymeric Precursor for Gallium Nitride Powders|url=https://pubs.acs.org/doi/10.1021/cm960419h|journal=Chemistry of Materials|language=en|volume=8|issue=12|pages=2708–2711|doi=10.1021/cm960419h|issn=0897-4756}}</ref>
|-
|[[Chemistry:Nitroxyl|Nitroxyl]]
|HNO
|bent
|
|14332-28-6
|
|-
|
|Al(NH<sub>2</sub>)(NH)
|polymer
|
|
|<ref name=":7" />
|-
|silicon dimide
|Si(NH)<sub>2</sub>
|
|
|
|
|-
|thionitrosyl hydride
|HNS
|bent
|
|14616-59-2
|<ref>{{Cite journal|last1=Nguyen|first1=Minh Tho|last2=Vanquickenborne|first2=L.G.|last3=Plisnier|first3=Michel|last4=Flammang|first4=Robert|date=January 1993|title=A mass spectrometric and ab initio molecular orbital characterization of thionitrosyl hydride (H-N=S)|url=http://www.tandfonline.com/doi/abs/10.1080/00268979300100111|journal=Molecular Physics|language=en|volume=78|issue=1|pages=111–119|doi=10.1080/00268979300100111|bibcode=1993MolPh..78..111N|issn=0026-8976}}</ref>
|-
|[[Chemistry:Sulfur diimide|sulfur diimide]]
|S(NH)<sub>2</sub>
|
|
|
|
|-
|[[Chemistry:Heptasulfur imide|Heptasulfur imide]]
|S<sub>7</sub>NH
|
|
|293-42-5
|<ref>{{cite journal |last1=Mendelsohn |first1=M.H. |last2=Jolly |first2=W.L. |title=Reactions of the heptasulfur imide anion |journal=Journal of Inorganic and Nuclear Chemistry |date=January 1973 |volume=35 |issue=1 |pages=95–99 |doi=10.1016/0022-1902(73)80614-1|s2cid=98171750 |url=https://escholarship.org/uc/item/97d7b60v }}</ref>
|-
|1,2,3,4,5,7,6,8-Hexathiadiazocane
1,3-Hexasulfurdiimide
|H<sub>2</sub>N<sub>2</sub>S<sub>6</sub>
|
|
|1003-75-4
|
|-
|1,2,3,4,6,7,5,8-Hexathiadiazocane
1,4-Hexasulfurdiimide
|H<sub>2</sub>N<sub>2</sub>S<sub>6</sub>
|
|
|1003-76-5
|
|-
|1,2,3,5,6,7,4,8-Hexathiadiazocane
1,5-Hexasulfurdiimide
|H<sub>2</sub>N<sub>2</sub>S<sub>6</sub>
|
|
|
|
|-
|1,2,3,5,7,4,6,8-Pentathiatriazocane
|H<sub>3</sub>N<sub>3</sub>S<sub>5</sub>
|
|
|638-50-6
|
|-
|
|ScNH
|
|
|
|<ref name=":2" />
|-
|
|Ga<sub>2</sub>(NH)<sub>3</sub>
|polymer
|
|
|<ref name=":7" />
|-
|
|YNH
|
|
|
|<ref name=":2" />
|-
|
|BaNH
|linear
|
|
|<ref name=":4" />
|-
|
|LaNH
|linear
|C∞v
|
|<ref name=":3" /><ref name=":5">{{Cite journal|last1=Zhang|first1=Yuchen|last2=Nyambo|first2=Silver|last3=Yang|first3=Dong-Sheng|date=2018-12-21|title=Mass-analyzed threshold ionization spectroscopy of lanthanide imide LnNH (Ln = La and Ce) radicals from N–H bond activation of ammonia|url=http://aip.scitation.org/doi/10.1063/1.5064597|journal=The Journal of Chemical Physics|language=en|volume=149|issue=23|pages=234301|doi=10.1063/1.5064597|pmid=30579310|bibcode=2018JChPh.149w4301Z|s2cid=58639516|issn=0021-9606}}</ref>
|-
|
|CeNH
|linear
|C∞v
|
|<ref name=":5" />
|-
|Uranimine nitride 
|N≡U═N−H
|
|
|
|<ref name=":10">{{Cite journal|last1=Wang|first1=Xuefeng|last2=Andrews|first2=Lester|last3=Vlaisavljevich|first3=Bess|last4=Gagliardi|first4=Laura|date=2011-04-18|title=Combined Triple and Double Bonds to Uranium: The N≡U═N−H Uranimine Nitride Molecule Prepared in Solid Argon|url=https://pubs.acs.org/doi/10.1021/ic2003244|journal=Inorganic Chemistry|language=en|volume=50|issue=8|pages=3826–3831|doi=10.1021/ic2003244|pmid=21405096|issn=0020-1669}}</ref>
|-
|Uranimine dihydride
|HN═UH<sub>2</sub>
|
|
|
|<ref name=":10" />
|-
|}
Molecular imines of other actinides called neptunimine and plutonimine have been postulated to exist in the gas phase or noble gas matrix.<ref>{{Cite journal|last1=Li|first1=Peng|last2=Niu|first2=Wenxia|last3=Gao|first3=Tao|date=2015-11-25|title=Systematic analysis of structural and spectroscopic properties of neptunimine (HN=NpH2) and plutonimine (HN=PuH2)|url=https://doi.org/10.1007/s00894-015-2856-1|journal=Journal of Molecular Modeling|language=en|volume=21|issue=12|pages=316|doi=10.1007/s00894-015-2856-1|pmid=26608606|s2cid=7587370|issn=0948-5023}}</ref>

==References==
{{Reflist}}

[[Category:Nitrogen compounds]]
[[Category:Hydrogen compounds]]

{{Sourceattribution|Inorganic imide}}