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Revision as of 09:13, 24 October 2011 editBeetstra (talk | contribs)Edit filter managers, Administrators172,031 edits Script assisted update of identifiers for the Chem/Drugbox validation project (updated: 'ChEBI').← Previous edit		Latest revision as of 14:36, 12 July 2024 edit undoBernanke's Crossbow (talk | contribs)Extended confirmed users7,789 edits →Use in organic chemistry: alkene reduction
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	{{Chembox		{{Chembox
			| Watchedfields =dkmrodkrg
	| verifiedrevid = 438147761
			| verifiedrevid = 457117309
	| ImageFileL1 = lithium-aluminium-hydride.png
			| Name = Lithium aluminium hydride
	| ImageSizeL1 = 125px
			| ImageFile =
	| ImageNameL1 = Wireframe model of lithium aluminium hydride
	| ImageFileR1 = Lithium-aluminium-hydride-layer-3D-balls.png		| ImageFileL1 = lithium aluminium hydride.svg
			| ImageNameL1 = Wireframe model of lithium aluminium hydride
	| ImageSizeR1 = 125px
	| ImageNameR1 = Unit cell ball and stick model of lithium aluminium hydride		| ImageFileR1 = Lithium-aluminium-hydride-layer-3D-balls.png
	| ImageFile2 = Lithium aluminium hydride 100g.jpg		| ImageNameR1 = Unit cell ball and stick model of lithium aluminium hydride
	| ImageName2 = 100 grams of lithium aluminium hydride		| ImageFile2 = Lithium aluminium hydride.jpg
	| PIN = Lithium aluminium hydride		| ImageName2 = Lithium aluminium hydride
			| ImageSize2 =
	| SystematicName = Lithium alumanuide
			| PIN = Lithium tetrahydridoaluminate(III)
	| OtherNames = Lithal<br />
			| SystematicName = Lithium alumanuide
	Lithium alanate<br />
			| OtherNames = {{ubl|Lithium aluminium hydride|Lithal|Lithium alanate|Lithium aluminohydride|Lithium tetrahydridoaluminate}}
	Lithium aluminohydride<br />
			| IUPACName =
	Lithium tetrahydridoaluminate<br />
			| Section1 = {{Chembox Identifiers
	Lithium tetrahydridoaluminate(III)
			| Abbreviations = LAH
	| Section1 = {{Chembox Identifiers
			| InChI = 1S/Al.Li.4H/q-1;+1;;;;
	| Abbreviations = LAH
	| InChI = 1S/Al.Li.4H/q-1;+1;;;;
	| InChIKey1 = OCZDCIYGECBNKL-UHFFFAOYSA-N		| InChIKey1 = OCZDCIYGECBNKL-UHFFFAOYSA-N
	| CASNo = 16853-85-3		| CASNo = 16853-85-3
	| CASNo_Ref = {{cascite|correct|CAS}}		| CASNo_Ref = {{cascite|correct|CAS}}
			| CASNo1_Ref = {{cascite|correct|??}}
	| CASNo1 = 14128-54-2
	| CASNo1_Comment = (<sup>2</sup>H<sub>4</sub>)		| CASNo1 = 14128-54-2
			| CASNo1_Comment = (<sup>2</sup>H<sub>4</sub>)
	| CASNo_Ref = {{cascite|correct|CAS}}		| UNII_Ref = {{fdacite|correct|FDA}}
	| PubChem = 28112		| UNII = 77UJC875H4
			| PubChem = 28112
	| PubChem_Ref = {{Pubchemcite}}
	| PubChem1 = 11062293		| PubChem1 = 11062293
	| PubChem1_Comment = (<sup>2</sup>H<sub>4</sub>)		| PubChem1_Comment = (<sup>2</sup>H<sub>4</sub>)
			| PubChem2 = 11094533
	| PubChem1_Ref = {{Pubchemcite}}
			| PubChem2_Comment = (<sup>3</sup>H<sub>4</sub>)
	| PubChem2 = 11094533
			| ChemSpiderID = 26150
	| PubChem2_Comment = (<sup>3</sup>H<sub>4</sub>)
			| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
	| PubChem2_Ref = {{Pubchemcite}}
			| EINECS = 240-877-9
	| ChemSpiderID = 26150
	| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}		| ChEBI_Ref = {{ebicite|correct|EBI}}
	| EINECS = 240-877-9
	| ChEBI_Ref = {{ebicite|correct|EBI}}
	| ChEBI = 30142		| ChEBI = 30142
	| RTECS = BD0100000		| RTECS = BD0100000
	| SMILES = .		| SMILES = .
	| StdInChI_Ref = {{stdinchicite|correct|chemspider}}		| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
	| StdInChI = 1S/Al.Li.4H/q-1;+1;;;;		| StdInChI = 1S/Al.Li.4H/q-1;+1;;;;
	| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}		| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
	| StdInChIKey = OCZDCIYGECBNKL-UHFFFAOYSA-N		| StdInChIKey = OCZDCIYGECBNKL-UHFFFAOYSA-N
	| Gmelin = 13167}}		| Gmelin = 13167
			| UNNumber = 1410
	| Section2 = {{Chembox Properties
			}}
	| Formula = LiAlH<sub>4</sub>
			| Section2 = {{Chembox Properties
	| MolarMass = 37.95 g/mol
			| Formula = {{chem2|Li}}
	| Appearance = white crystals (pure samples)<br />grey powder (commercial material) <br> ]
			| Li=1|Al=1|H=4
			| Appearance = white crystals (pure samples)<br />grey powder (commercial material) <br /> ]
			| Odor = odorless
	| Density = 0.917 g/cm<sup>3</sup>, solid		| Density = 0.917 g/cm<sup>3</sup>, solid
	| Solubility = reactive		| Solubility = Reacts
			| Solvent1 = tetrahydrofuran
	| MeltingPt = 150 °C (423 K), decomposing
			| Solubility1 = 112.332 g/L
			| Solvent2 = diethyl ether
			| Solubility2= 39.5 g/(100 mL)
			| MeltingPtC = 150
			| MeltingPt_notes = (decomposes)
	| BoilingPt =		| BoilingPt =
	}}		}}
	| Section3 = {{Chembox Structure		| Section3 = {{Chembox Structure
	| Coordination =		| Coordination =
	| CrystalStruct = ]		| CrystalStruct = ]
	| SpaceGroup = P2<sub>1</sub>c		| SpaceGroup = ''P''2<sub>1</sub>/''c''
	| Dipole =		| Dipole =
	}}		}}
	| Section7 = {{Chembox Hazards		| Section4 = {{Chembox Thermochemistry
			| DeltaHf = −117 kJ/mol
	| Reference = <ref>{{CLP Regulation|index=001-002-00-4|page=340}}</ref>
			| DeltaGf = −48.4 kJ/mol
	| EUIndex = 001-002-00-4
			| Entropy = 87.9 J/(mol·K)
	| GHSPictograms = {{GHS02|Water-react. 1}}
			| HeatCapacity = 86.4 J/(mol·K)
	| GHSSignalWord = DANGER
			}}
	| HPhrases = {{H-phrases|260}}
			| Section5 =
	| ExternalMSDS = |
			| Section6 =
	| MainHazards = highly flammable
			| Section7 = {{Chembox Hazards
			| Hazards_ref = <ref>{{CLP Regulation|index=001-002-00-4|page=472}}</ref>
			| GHSPictograms = {{GHS02}}{{GHS05}}
			| GHSSignalWord = DANGER
			| HPhrases = {{H-phrases|260|314}}
			| PPhrases = {{P-phrases|223|231+232|280|305+351+338|370+378|422}}<ref name="sigma">{{Sigma-Aldrich|id=199877|name=Lithium aluminium hydride|accessdate=2018-06-1}}</ref>
			| ExternalSDS =
	| NFPA-H = 3		| NFPA-H = 3
	| NFPA-R = 2		| NFPA-R = 2
	| NFPA-F = 2		| NFPA-F = 2
	| NFPA-O = W		| NFPA-S = W
			| NFPA_ref = <ref></ref>
	| FlashPt = 125 °C
			| FlashPtC = 125
	| RSPhrases = {{R15}}, {{S7/8}}, {{S24/25}}, {{S43}}
	}}		}}
	| Section8 = {{Chembox Related		| Section8 = {{Chembox Related
	| Function = ]		| OtherFunction_label = ]
	| OtherFunctn = ]<br />]<br />]		| OtherFunction = ]<br />]<br />]<br />]
	}}		}}
	}}		}}
	'''Lithium aluminium hydride''', commonly abbreviated to '''LAH''' or known as '''LithAl''', is an ] with the ] ]]]. It was discovered by Finholt, Bond and Schlesinger in 1947.<ref name="Schlessinger">{{cite journal|doi=10.1021/ja01197a061|year=1947|last1=Finholt|first1=A. E.|last2=Bond|first2=A. C.|last3=Schlesinger|first3=H. I.|journal=Journal of the American Chemical Society|volume=69|pages=1199|issue=5}}</ref> This compound is used as a ] in ], especially for the reduction of ]s, ]s, and ]s. The solid is dangerously reactive toward ], releasing gaseous ] (H<sub>2</sub>). Some related derivatives have been discussed for the ].		'''Lithium aluminium hydride''', commonly abbreviated to '''LAH''', is an ] with the ] {{chem2|Li|auto=1}} or {{chem2|LiAlH4}}. It is a white solid, discovered by Finholt, Bond and ] in 1947.<ref name="Schlessinger">{{cite journal|last1=Finholt|first1=A. E.|last2=Bond|first2=A. C.|last3=Schlesinger|first3=H. I.|title=Lithium Aluminum Hydride, Aluminum Hydride and Lithium Gallium Hydride, and Some of their Applications in Organic and Inorganic Chemistry|journal=Journal of the American Chemical Society|year=1947|volume=69|issue=5|pages=1199–1203|doi=10.1021/ja01197a061}}</ref> This compound is used as a ] in ], especially for the reduction of ]s, ]s, and ]s. The solid is dangerously reactive toward water, releasing gaseous ] (H<sub>2</sub>). Some related derivatives have been discussed for ].
	==Properties, structure, preparation==		== Properties, structure, preparation ==
	] image of LAH powder]]		] image of LAH powder]]
	LAH is a white solid, but commercial samples are usually gray due to contamination.<ref name=africa>{{cite book|url=http://books.google.com/?id=1wS3aWR5SO4C&pg=PA143|page=143|title=Sasol Encyclopaedia of Science and Technology|author=Gerrans, G.C. and Hartmann-Petersen, P.|publisher=New Africa Books|year=2007|isbn=1869283848}}</ref> This material can be purified by recrystallization from ]. Large-scale purifications employ a ]. Commonly, the impure gray material is used in synthesis, since the impurities are innocuous and can be easily separated from the organic products. The pure powdered material is ], but not its large crystals.<ref>{{cite book|url=http://books.google.com/?id=-fo-Z3TfB3YC&pg=PA134|page=134|title=Practical organic synthesis: a student's guide|author=Keese, Reinhart; Brändle, Martin and Toube, Trevor Philip|publisher=John Wiley and Sons|year=2006|isbn=0470029668}}</ref> Some commercial materials contain ] to inhibit reactions with atmospheric moisture, but more commonly it is packed in moisture-proof plastic sacks.<ref>{{cite journal|title=Dehydrogenation kinetics of as-received and ball-milled LiAlH4|url=http://dcwww.camd.dtu.dk/Nabiit/Dehydrogenation%20kinetics%20of%20as-received%20and%20ball-milled%20LiAlH4.pdf|doi=10.1016/j.jssc.2005.09.027|year=2005|last1=Andreasen|first1=A.|last2=Vegge|first2=T.|last3=Pedersen|first3=A.S.|journal=Journal of Solid State Chemistry|volume=178|pages=3672|issue=12}}</ref>		LAH is a colourless solid but commercial samples are usually gray due to contamination.<ref name=africa>{{cite encyclopedia |author1=Gerrans, G. C. |author2=Hartmann-Petersen, P. | title = Lithium Aluminium Hydride | encyclopedia = Sasol Encyclopaedia of Science and Technology | publisher = New Africa Books | year = 2007 | page = 143 | isbn = 978-1-86928-384-1 | url = https://books.google.com/books?id=1wS3aWR5SO4C&pg=PA143 }}</ref> This material can be purified by recrystallization from ]. Large-scale purifications employ a ]. Commonly, the impure gray material is used in synthesis, since the impurities are innocuous and can be easily separated from the organic products. The pure powdered material is ], but not its large crystals.<ref>{{cite book |author1=Keese, R. |author2=Brändle, M. |author3=Toube, T. P. | title = Practical Organic Synthesis: A Student's Guide | publisher = John Wiley and Sons | year = 2006 | page = | isbn = 0-470-02966-8 | url = https://archive.org/details/practicalorganic0000kees |url-access=registration }}</ref> Some commercial materials contain ] to inhibit reactions with atmospheric moisture, but more commonly it is packed in moisture-proof plastic sacks.<ref>{{cite journal | last1 = Andreasen | first1 = A. | last2 = Vegge | first2 = T. | last3 = Pedersen | first3 = A. S. | title = Dehydrogenation Kinetics of as-Received and Ball-Milled LiAlH<sub>4</sub> | journal = Journal of Solid State Chemistry | year = 2005 | volume = 178 | issue = 12 | pages = 3672–3678 | doi = 10.1016/j.jssc.2005.09.027 | url = http://dcwww.camd.dtu.dk/Nabiit/Dehydrogenation%20kinetics%20of%20as-received%20and%20ball-milled%20LiAlH4.pdf | bibcode = 2005JSSCh.178.3672A | access-date = 2010-05-07 | archive-url = https://web.archive.org/web/20160303221434/http://dcwww.camd.dtu.dk/Nabiit/Dehydrogenation%20kinetics%20of%20as-received%20and%20ball-milled%20LiAlH4.pdf | archive-date = 2016-03-03 | url-status = dead }}</ref>
	LAH violently reacts with ], including atmospheric moisture. The reaction proceeds according the following idealized equation:<ref name=africa/>		LAH violently reacts with water, including atmospheric moisture, to liberate dihydrogen gas. The reaction proceeds according to the following idealized equation:<ref name="africa" />
	:LiAlH<sub>4</sub> + 4 H<sub>2</sub>O → LiOH + Al(OH)<sub>3</sub> + 4 H<sub>2</sub>		:{{chem2|Li + 4 H2O → LiOH + Al(OH)3 + 4 H2}}
	This reaction provides a useful method to generate hydrogen in the laboratory. Aged, air-exposed samples often appear white because they have absorbed enough moisture to generate a mixture of the white compounds ] and ].<ref name="sittig">{{cite book|last=Pohanish|first=Richard P.|title=Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens|publisher=William Andrew Publishing |year=2008|edition=5th|pages=1540|isbn= 978-0-8155-1553-1}}</ref>		This reaction provides a useful method to generate hydrogen in the laboratory. Aged, air-exposed samples often appear white because they have absorbed enough moisture to generate a mixture of the white compounds ] and ].<ref name="sittig">{{cite book | last = Pohanish | first = R. P. | title = Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens | edition = 5th | publisher = William Andrew Publishing | year = 2008 | page = 1540 | isbn = 978-0-8155-1553-1 }}</ref>
	===Structure===		=== Structure ===
	]		]
	LAH crystallizes in the ] ] P2<sub>1</sub>c. The ] is defined as follows: a = 4.82, b = 7.81, and c = 7.92 Å, α = γ = 90° and β = 112°. The solid consists of Li<sup>+</sup> centers surrounded by five {{chem|AlH|4|-}} ]. The Li<sup>+</sup> centers are bonded to one ] atom from each of the surrounding tetrahedra creating a ] arrangement. At high pressures (>2.2 GPa) a phase transition may occur to give β-LAH.<ref name="crystal_structure">{{cite journal|author=Løvvik, O.M.; Opalka, S.M.; Brinks, H.W.; Hauback, B.C.|doi=10.1103/PhysRevB.69.134117|title=Crystal structure and thermodynamic stability of the lithium alanates LiAlH4 and Li3AlH6|year=2004|journal=Physical Review B|volume=69|pages=134117|issue=13}}</ref>		LAH crystallizes in the ] ] ''P''2<sub>1</sub>/''c''. The ] has the dimensions: ''a'' = 4.82, ''b'' = 7.81, and ''c'' = 7.92 Å, α = γ = 90° and β = 112°. In the structure, {{chem2|Li+}} ] are surrounded by five {{chem2|−}} ], which have ]. The {{chem2|Li+}} cations are bonded to one ] atom from each of the surrounding tetrahedral {{chem2|−}} anion creating a ] arrangement. At high pressures (>2.2 GPa) a phase transition may occur to give β-LAH.<ref name="crystal_structure">{{cite journal |author1=Løvvik, O. M. |author2=Opalka, S. M. |author3=Brinks, H. W. |author4=Hauback, B. C. | title = Crystal Structure and Thermodynamic Stability of the Lithium Alanates LiAlH<sub>4</sub> and Li<sub>3</sub>AlH<sub>6</sub> | journal = Physical Review B | year = 2004 | volume = 69 | issue = 13 | pages = 134117 | doi = 10.1103/PhysRevB.69.134117 |bibcode=2004PhRvB..69m4117L }}</ref>
	] pattern of as-received LiAlH<sub>4</sub>. The asterisk designates an impurity, possibly ].]]		] pattern of as-received {{chem2|Li}}. The asterisk designates an impurity, possibly ].]]
	===Preparation===		=== Preparation ===
	LAH was first prepared from the reaction between ] (LiH) and ]:<ref name="Schlessinger"/><ref name=africa/>		{{chem2|Li}} was first prepared from the reaction between ] (LiH) and ]:<ref name="Schlessinger" /><ref name="africa" />
	:4 LiH + AlCl<sub>3</sub> → LiAlH<sub>4</sub> + 3 LiCl		:{{chem2|4 LiH + AlCl3 → Li + 3 LiCl}}
	In addition to this method, the industrial synthesis entails the initial preparation of sodium aluminium hydride from the elements under high pressure and temperature:<ref name="HollemanAF">{{cite book|author=Holleman, A. F., Wiberg, E., Wiberg, N.|title=Lehrbuch der Anorganischen Chemie, 102nd ed.|publisher=de Gruyter|year=2007|isbn=978-3-11-017770-1|url=http://books.google.com/?id=mahxPfBdcxcC&printsec=frontcover}}</ref>
	:Na + Al + 2 H<sub>2</sub> → NaAlH<sub>4</sub>
			In addition to this method, the industrial synthesis entails the initial preparation of ] from the elements under high pressure and temperature:<ref name="HollemanAF">{{cite book | author = Holleman, A. F., Wiberg, E., Wiberg, N. | title = Lehrbuch der Anorganischen Chemie | edition = 102nd | publisher = de Gruyter | year = 2007 | isbn = 978-3-11-017770-1 | url = https://books.google.com/books?id=mahxPfBdcxcC }}</ref>
	LAH is then prepared by ] according to:
			:{{chem2|Na + Al + 2 H2 → Na}}
	:NaAlH<sub>4</sub> + LiCl → LiAlH<sub>4</sub> + NaCl
			{{chem2|Li}} is then prepared by a ] according to:
	which proceeds in a high yield of LAH. LiCl is removed by ] from an ]eal solution of LAH, with subsequent precipitation of LAH to yield a product containing around 1% ''w''/''w'' LiCl.<ref name="HollemanAF"/>
			:{{chem2|Na + LiCl → Li + NaCl}}
			which proceeds in a high yield. ] is removed by ] from an ] solution of LAH, with subsequent precipitation of LAH to yield a product containing around 1% ''w''/''w'' LiCl.<ref name="HollemanAF" />
			An alternative preparation starts from LiH, and metallic Al instead of {{chem2|AlCl3}}. Catalyzed by a small quantity of {{chem2|TiCl3}} (0.2%), the reaction proceeds well using ] as solvent. This method avoids the cogeneration of salt.<ref>{{cite journal |last1=Xiangfeng |first1=Liu |last2=Langmi |first2=Henrietta W. |last3=McGrady |first3=G. Sean |last4=Craig |first4=M. Jensen |last5=Beattie |first5=Shane D. |last6=Azenwi |first6=Felix F. |title=Ti-Doped LiAlH<sub>4</sub> for Hydrogen Storage: Synthesis, Catalyst Loading and Cycling Performance |journal=J. Am. Chem. Soc. |year=2011 |volume=133 |issue=39 |pages=15593–15597|doi=10.1021/ja204976z|pmid=21863886 }}</ref>
			=== Solubility data ===
	===Solubility data===
	<div style="float:left;margin-left:0.5em;">
	{|class="wikitable" style="text-align:center"		{|class="wikitable" style="text-align:center"
	|+ Solubility of LiAlH<sub>4</sub> (mol/L)<ref name=sol>{{cite journal|doi=10.1007/BF00853610|title=Solubility of lithium aluminum hydride and lithium borohydride in diethyl ether|year=1971|last1=Mikheeva|first1=V. I.|last2=Troyanovskaya|first2=E. A.|journal=Bulletin of the Academy of Sciences of the USSR Division of Chemical Science|volume=20|pages=2497|issue=12}}</ref>		|+ Solubility of {{chem2|Li}} (mol/L)<ref name=sol>{{cite journal | last1 = Mikheeva | first1 = V. I. | last2 = Troyanovskaya | first2 = E. A. | title = Solubility of Lithium Aluminum Hydride and Lithium Borohydride in Diethyl Ether | journal = Bulletin of the Academy of Sciences of the USSR Division of Chemical Science | year = 1971 | volume = 20 | issue = 12 | pages = 2497–2500 | doi = 10.1007/BF00853610 }}</ref>
			|-
	|- bgcolor=#ffdead
			!rowspan=2 |Solvent
	| || colspan=5|'''Temperature (°C)'''
			!colspan=5|Temperature (°C)
	|- bgcolor=#ffdead		|- bgcolor=#ffdead
	| '''Solvent''' || '''0''' || '''25''' || '''50''' || '''75''' || '''100'''		! 0 !! 25 !! 50 !! 75 !! 100
	|-		|-
	| bgcolor=#ffdead align=left|] || – || 5.92 || – || – || –		!]
			| – || 5.92 || – || – || –
	|-		|-
			!]
	| bgcolor=#ffdead align=left|] || – || 2.96 || – || – || –
			| – || 2.96 || – || – || –
	|-		|-
			!]
	| bgcolor=#ffdead align=left|] || 1.29 || 1.80 || 2.57 || 3.09 || 3.34
			| 1.29 || 1.80 || 2.57 || 3.09 || 3.34
	|-		|-
	| bgcolor=#ffdead align=left|] || 0.26 || 1.29 || 1.54 || 2.06 || 2.06		!]
			| 0.26 || 1.29 || 1.54 || 2.06 || 2.06
	|-		|-
			!]
	| bgcolor=#ffdead align=left|Triglyme || 0.56 || 0.77 || 1.29 || 1.80 || 2.06
			| 0.56 || 0.77 || 1.29 || 1.80 || 2.06
	|-		|-
			!]
	| bgcolor=#ffdead align=left|Tetraglyme || 0.77 || 1.54 || 2.06 || 2.06 || 1.54
			| 0.77 || 1.54 || 2.06 || 2.06 || 1.54
	|-		|-
			!]
	| bgcolor=#ffdead align=left|] || – || 0.03 || – || – || –
			| – || 0.03 || – || – || –
	|-		|-
			!]
	| bgcolor=#ffdead align=left|Dibutyl ether || – || 0.56 || – || – || –
			| – || 0.56 || – || – || –
	|}		|}
	</div>
	LAH is soluble in many ]al solutions. However, it may spontaneously decompose due to the presence of catalytic impurities, though, it appears to be more stable in ] (THF). Thus, THF is preferred over, e.g., ], despite the lower solubility.<ref name=sol/>		LAH is soluble in many ] solutions. However, it may spontaneously decompose due to the presence of catalytic impurities, though, it appears to be more stable in ] (THF). Thus, THF is preferred over, e.g., ], despite the lower solubility.<ref name="sol" />
	{{clear}}
			=== Thermal decomposition ===
	===Thermodynamic data===
			LAH is ] at room temperature. During prolonged storage it slowly decomposes to {{chem2|Li3}} (lithium hexahydridoaluminate) and ].<ref name="Dymova">{{cite journal |author1=Dymova T. N. |author2=Aleksandrov, D. P. |author3=Konoplev, V. N. |author4=Silina, T. A. |author5=Sizareva |author6=A. S. | journal = Russian Journal of Coordination Chemistry | year = 1994 | volume = 20 | pages = 279 }}</ref> This process can be accelerated by the presence of ] elements, such as ], ] or ].
	The table summarizes ] data for LAH and reactions involving LAH,<ref name="InorganicHandbook" /><ref>{{cite journal|doi=10.1021/je60018a020|title=Heats and Free Energies of Formation of the Alkali Aluminum Hydrides and of Cesium Hydride|year=1963|last1=Smith|first1=Martin B.|last2=Bass|first2=George E.|journal=Journal of Chemical & Engineering Data|volume=8|pages=342|issue=3}}</ref> in the form of ] ], ] and ] change, respectively.
			] of as-received {{chem2|Li}}.]]
			When heated LAH decomposes in a three-step ]:<ref name="Dymova" /><ref>{{cite journal | last1 = Dilts | first1 = J. A. | last2 = Ashby | first2 = E. C. | title = Thermal Decomposition of Complex Metal Hydrides | journal = Inorganic Chemistry | year = 1972 | volume = 11 | issue = 6 | pages = 1230–1236 | doi = 10.1021/ic50112a015 }}</ref><ref name="Blanchard">{{cite journal | last1 = Blanchard | first1 = D. | last2 = Brinks | first2 = H. | last3 = Hauback | first3 = B. | last4 = Norby | first4 = P. | title = Desorption of LiAlH<sub>4</sub> with Ti- and V-Based Additives | journal = Materials Science and Engineering B | year = 2004 | volume = 108 | issue = 1–2 | pages = 54–59 | doi = 10.1016/j.mseb.2003.10.114 }}</ref>
			{{NumBlk|:|{{chem2|3 Li → Li3 + 2 Al + 3 H2}} |{{EquationRef|R1}}}}
			{{NumBlk|:|{{chem2|2 Li3 → 6 LiH + 2 Al + 3 H2}} |{{EquationRef|R2}}}}
			{{NumBlk|:|{{chem2|2 LiH + 2 Al → 2 LiAl + H2}} |{{EquationRef|R3}}}}
			{{EquationNote|R1}} is usually initiated by the ] of LAH in the temperature range 150–170&nbsp;°C,<ref>{{cite journal | last1 = Chen | first1 = J. | last2 = Kuriyama | first2 = N. | last3 = Xu | first3 = Q. | last4 = Takeshita | first4 = H. T. | last5 = Sakai | first5 = T. | title = Reversible Hydrogen Storage via Titanium-Catalyzed LiAlH<sub>4</sub> and Li<sub>3</sub>AlH<sub>6</sub> | journal = The Journal of Physical Chemistry B | year = 2001 | volume = 105 | issue = 45 | pages = 11214–11220 | doi = 10.1021/jp012127w }}</ref><ref>{{cite journal | last1 = Balema | first1 = V. | last2 = Pecharsky | first2 = V. K. | last3 = Dennis | first3 = K. W. | title = Solid State Phase Transformations in LiAlH<sub>4</sub> during High-Energy Ball-Milling | journal = Journal of Alloys and Compounds | year = 2000 | volume = 313 | issue = 1–2 | pages = 69–74 | doi = 10.1016/S0925-8388(00)01201-9 | url = https://zenodo.org/record/1260143 }}</ref><ref name="Andreasen">{{cite journal | last1 = Andreasen | first1 = A. | title = Effect of Ti-Doping on the Dehydrogenation Kinetic Parameters of Lithium Aluminum Hydride | journal = Journal of Alloys and Compounds | year = 2006 | volume = 419 | issue = 1–2 | pages = 40–44 | doi = 10.1016/j.jallcom.2005.09.067 }}</ref> immediately followed by decomposition into solid {{chem2|Li3}}, although {{EquationNote|R1}} is known to proceed below the melting point of {{chem2|Li}} as well.<ref>{{cite journal | last1 = Andreasen | first1 = A. | last2 = Pedersen | first2 = A. S. | last3 = Vegge | first3 = T. | title = Dehydrogenation Kinetics of as-Received and Ball-Milled LiAlH<sub>4</sub> | journal = Journal of Solid State Chemistry | year = 2005 | volume = 178 | issue = 12 | pages = 3672–3678 | doi = 10.1016/j.jssc.2005.09.027 | bibcode = 2005JSSCh.178.3672A }}</ref> At about 200&nbsp;°C, {{chem2|Li3}} decomposes into LiH ({{EquationNote|R2}})<ref name="Dymova" /><ref name="Blanchard" /><ref name="Andreasen" /> and Al which subsequently convert into LiAl above 400&nbsp;°C ({{EquationNote|R3}}).<ref name="Blanchard" /> Reaction R1 is effectively irreversible. {{EquationNote|R3}} is reversible with an equilibrium pressure of about 0.25 bar at 500&nbsp;°C. {{EquationNote|R1}} and {{EquationNote|R2}} can occur at room temperature with suitable catalysts.<ref>{{cite journal | last1 = Balema | first1 = V. | first2 = J. W. | last2 = Wiench | first3 = K. W. | last3 = Dennis | first4 = M. | last4 = Pruski | first5 = V. K. | last5 = Pecharsky | title = Titanium Catalyzed Solid-State Transformations in LiAlH<sub>4</sub> During High-Energy Ball-Milling | journal = Journal of Alloys and Compounds | year = 2001 | volume = 329 | issue = 1–2 | pages = 108–114 | doi = 10.1016/S0925-8388(01)01570-5 | url = https://zenodo.org/record/1260145 }}</ref>
	<center>
	{|class="wikitable" style="text-align:center"
	|+ Thermodynamic data for reactions involving LiAlH<sub>4</sub>		=== Thermodynamic data ===
			The table summarizes ] data for LAH and reactions involving LAH,<ref name="InorganicHandbook">{{cite book |last=Patnaik |first=P. |url=https://archive.org/details/Handbook_of_Inorganic_Chemistry_Patnaik |title=Handbook of Inorganic Chemicals |publisher=McGraw-Hill |year=2003 |isbn=978-0-07-049439-8 |page=}}</ref><ref>{{cite journal | last1 = Smith | first1 = M. B. | last2 = Bass | first2 = G. E. | title = Heats and Free Energies of Formation of the Alkali Aluminum Hydrides and of Cesium Hydride | journal = Journal of Chemical & Engineering Data | year = 1963 | volume = 8 | issue = 3 | pages = 342–346 | doi = 10.1021/je60018a020 }}</ref> in the form of ] ], ], and ] change, respectively.
			{|class="wikitable" style="margin:1em auto; text-align:center"
			|+ Thermodynamic data for reactions involving {{chem2|Li}}
	|- bgcolor=#ffdead		|- bgcolor=#ffdead
	! Reaction || ΔH° <br/>(kJ/mol) || ΔS° <br/>(J/(mol·K)) || ΔG° <br/>(kJ/mol) || Comment		! Reaction || ΔH° <br />(kJ/mol) || ΔS° <br />(J/(mol·K)) || ΔG° <br />(kJ/mol) || Comment
	|-		|-
	| align=left|Li (s) + Al (s) + 2 H<sub>2</sub>(g) → LiAlH<sub>4</sub> (s) || −116.3 || −240.1 || −44.7 || Standard formation from the elements.		| align = left|{{chem2|Li (s) + Al (s) + 2 H2 (g) → Li}} (s) || −116.3 || −240.1 || −44.7 || Standard formation from the elements.
	|-		|-
	| align=left|LiH (s) + Al (s) + 3/2 H<sub>2</sub> (g) → LiAlH<sub>4</sub> (s) || −25.6 || −170.2 || 23.6 || Using ΔH°<sub>f</sub>(LiH) = −90.5, ΔS°<sub>f</sub>(LiH) = −69.9, and ΔG°<sub>f</sub>(LiH) = −68.3.		| align = left|LiH (s) + Al (s) + {{frac|3|2}} H<sub>2</sub> (g) → LiAlH<sub>4</sub> (s) || −95.6 || −180.2 || 237.6 || Using ΔH°<sub>f</sub>(LiH) = −90.579865, ΔS°<sub>f</sub>(LiH) = −679.9, and ΔG°<sub>f</sub>(LiH) = −67.31235744.
	|-		|-
	| align=left|LiAlH<sub>4</sub> (s) → LiAlH<sub>4</sub> (l) || 22 || – || – || Heat of fusion. Value might be unreliable.		| align = left|{{chem2|Li (s) → Li}} (l) || 22 || – || – || Heat of fusion. Value might be unreliable.
	|-		|-
	| align=left|LiAlH<sub>4</sub> (l) → ⅓ Li<sub>3</sub>AlH<sub>6</sub> (s) + ⅔ Al (s) + H<sub>2</sub> (g) || 3.46 || 104.5 || −27.68 || ΔS° calculated from reported values of ΔH° and ΔG°.		| align = left|LiAlH<sub>4</sub> (l) → {{1/3}} Li<sub>3</sub>AlH<sub>6</sub> (s) + {{2/3}} Al (s) + H<sub>2</sub> (g) || 3.46 || 104.5 || −27.68 || ΔS° calculated from reported values of ΔH° and ΔG°.
	|}		|}
	</center>
			== Applications ==
	===Thermal decomposition===
	LAH is ] at room temperature. During prolonged storage it slowly decomposes to Li<sub>3</sub>AlH<sub>6</sub> and LiH.<ref name="Dymova">{{cite journal|author=Dymova T. N.; Aleksandrov, D. P.; Konoplev, V. N.; Silina,T. A.; Sizareva; A. S.|journal=Russ. J. Coord. Chem.|volume= 20|page=279|year=1994}}</ref> This process can be accelerated by the presence of ] elements, such as ], ] or ].
	] of as-received LiAlH<sub>4</sub>.]]
	When heated LAH decomposes in a three-step ]:<ref name="Dymova"/><ref>{{cite journal|doi=10.1021/ic50112a015|title=Thermal decomposition of complex metal hydrides|year=1972|last1=Dilts|first1=J. A.|last2=Ashby|first2=E. C.|journal=Inorganic Chemistry|volume=11|pages=1230|issue=6}}</ref><ref name="Blanchard">{{cite journal|doi=10.1016/j.mseb.2003.10.114|title=Desorption of LiAlH4 with Ti- and V-based additives|year=2004|last1=Blanchard|first1=D|last2=Brinks|first2=H|last3=Hauback|first3=B|last4=Norby|first4=P|journal=Materials Science and Engineering B|volume=108|pages=54}}</ref>
	:3 LiAlH<sub>4</sub> → Li<sub>3</sub>AlH<sub>6</sub> + 2 Al + 3 H<sub>2</sub> (R1)
	:2 Li<sub>3</sub>AlH<sub>6</sub> → 6 LiH + 2 Al + 3 H<sub>2</sub> (R2)
	:2 LiH + 2 Al → 2 LiAl + H<sub>2</sub> (R3)
			=== Use in organic chemistry ===
	R1 is usually initiated by the ] of LAH in the temperature range 150–170 °C,<ref>{{cite journal|doi=10.1021/jp012127w|title=Reversible Hydrogen Storage via Titanium-Catalyzed LiAlH4and Li3AlH6|year=2001|last1=Chen|first1=Jun|last2=Kuriyama|first2=Nobuhiro|last3=Xu|first3=Qiang|last4=Takeshita|first4=Hiroyuki T.|last5=Sakai|first5=Tetsuo|journal=The Journal of Physical Chemistry B|volume=105|pages=11214|issue=45}}.</ref><ref>{{cite journal|doi=10.1016/S0925-8388(00)01201-9|title=Solid state phase transformations in LiAlH4 during high-energy ball-milling|first3=K.W|last3=Dennis|first2=V.K|year=2000|last2=Pecharsky|last1=Balema|first1=V|journal=Journal of Alloys and Compounds|volume=313|pages=69}}</ref><ref name="Andreasen">{{cite journal|doi=10.1016/j.jallcom.2005.09.067|title=Effect of Ti-doping on the dehydrogenation kinetic parameters of lithium aluminum hydride|year=2006|last1=Andreasen|first1=A|journal=Journal of Alloys and Compounds|volume=419|pages=40}}</ref> immediately followed by decomposition into solid Li<sub>3</sub>AlH<sub>6</sub>, although R1 is known to proceed below the melting point of LiAlH<sub>4</sub> as well.<ref>{{cite journal|doi=10.1016/j.jssc.2005.09.027|title=Dehydrogenation kinetics of as-received and ball-milled LiAlH<sub>4</sub>|year=2005|last1=Andreasen|first1=A|last2=Pedersen|first2=A S|last3=Vegge|first3=T|journal=Journal of Solid State Chemistry|volume=178|pages=3672|issue=12}}</ref> At about 200 °C, Li<sub>3</sub>AlH<sub>6</sub> decomposes into LiH (R2)<ref name="Dymova"/><ref name="Blanchard"/><ref name="Andreasen"/> and Al which subsequently convert into LiAl above 400 °C (R3).<ref name="Blanchard"/> Reaction R1 is effectively irreversible. R3 is reversible with an equilibrium pressure of about 0.25 bar at 500 °C. R1 and R2 can occur at room temperature with suitable catalysts.<ref>{{cite journal|doi=10.1016/S0925-8388(01)01570-5|title=Titanium catalyzed solid-state transformations in LiAlH<sub>4</sub> during high-energy ball-milling|year=2001|last1=Balema|first1=V|first2=J. W.|last2=Wiench|first3=K. W.|last3=Dennis|first4=M.|last4=Pruski|first5=V. K.|last5=Pecharsky|journal=Journal of Alloys and Compounds|volume=329|pages=108}}</ref>
			Lithium aluminium hydride (LAH) is widely used in organic chemistry as a ].<ref name="africa" /> It is more powerful than the related ] ] owing to the weaker Al-H bond compared to the B-H bond.<ref>{{cite journal | author = Brown, H. C. | title = Reductions by Lithium Aluminum Hydride | journal = Organic Reactions | year = 1951 | volume = 6 | page = 469 | doi = 10.1002/0471264180.or006.10 | isbn = 0-471-26418-0 }}</ref> Often as a solution in ] and followed by an acid workup, it will convert ]s, ]s, ]s, ], and ]s into the corresponding ] (see: ]). Similarly, it converts ],<ref>{{OrgSynth |author1=Seebach, D.|author2=Kalinowski, H.-O.|author3=Langer, W.|author4=Crass, G.|author5=Wilka, E.-M. | title = Chiral Media for Asymmetric Solvent Inductions. (S,S)-(+)-1,4-bis(Dimethylamino)-2,3-Dimethoxybutane from (R,R)-(+)-Diethyl Tartrate | collvol = 7 | collvolpages = 41 | year = 1991 | prep = cv7p0041 }}</ref><ref>{{OrgSynth |author1=Park, C. H.|author2=Simmons, H. E. | title = Macrocyclic Diimines: 1,10-Diazacyclooctadecane | collvol = 6 | collvolpages = 382 | volume = 54 | pages = 88 | year = 1974 | prep = cv6p0382 }}</ref> ], ], ], ],<ref>{{OrgSynth |author1=Chen, Y. K.|author2=Jeon, S.-J.|author3=Walsh, P. J.|author4=Nugent, W. A. | title = (2S)-(−)-3-exo-(Morpholino)Isoborneol | volume = 82 | pages = 87 | year = 2005 | prep = v82p0087 }}</ref> and ]s into the ]s (see: ]). It reduces ]s into the corresponding tertiary amines. Reactivity can be tuned by replacing hydride groups ]. Due to its pyrophoric nature, instability, toxicity, low shelf life and handling problems associated with its reactivity, it has been replaced in the last decade, both at the small-industrial scale and for large-scale reductions by the more convenient related reagent ], which exhibits similar reactivity but with higher safety, easier handling and better economics.<ref>{{Cite web | url = https://www.organic-chemistry.org/chemicals/reductions/sodiumbis(2-methoxyethoxy)aluminumhydride-red-al.shtm | title = Red-Al, Sodium bis(2-methoxyethoxy)aluminumhydride | publisher = Organic Chemistry Portal }}</ref>
			LAH is most commonly used for the reduction of ]s<ref>{{OrgSynth |author1=Reetz, M. T.|author2=Drewes, M. W.|author3=Schwickardi, R. | title = Preparation of Enantiomerically Pure α-N,N-Dibenzylamino Aldehydes: S-2-(N,N-Dibenzylamino)-3-Phenylpropanal | collvol = 10 | collvolpages = 256 | volume = 76 | pages = 110 | year = 1999 | prep = v76p0110 }}</ref><ref>{{OrgSynth |author1=Oi, R.|author2=Sharpless, K. B. | title = 3-<nowiki></nowiki>-1,5-Dihydro-3H-2,4-Benzodioxepine | collvol = 9 | collvolpages = 251 | volume = 73 | pages = 1 | year = 1996 | prep = cv9p0251 }}</ref> and ]s<ref>{{OrgSynth |author1=Koppenhoefer, B.|author2=Schurig, V. | title = (R)-Alkyloxiranes of High Enantiomeric Purity from (S)-2-Chloroalkanoic Acids via (S)-2-Chloro-1-Alkanols: (R)-Methyloxirane | collvol = 8 | collvolpages = 434 | volume = 66 | pages = 160 | year = 1988 | prep = cv8p0434 }}</ref> to primary alcohols; prior to the advent of LAH this was a difficult conversion involving ] metal in boiling ] (the ]). ]s and ]s<ref>{{OrgSynth |author1=Barnier, J. P.|author2=Champion, J.|author3=Conia, J. M. | title = Cyclopropanecarboxaldehyde | collvol = 7 | collvolpages = 129 | volume = 60 | pages = 25 | year = 1981 | prep = cv7p0129 }}</ref> can also be reduced to alcohols by LAH, but this is usually done using milder reagents such as }}]]; α, β-unsaturated ketones are reduced to allylic alcohols.<ref>{{OrgSynth |author1=Elphimoff-Felkin, I.|author2=Sarda, P. | title = Reductive Cleavage of Allylic Alcohols, Ethers, or Acetates to Olefins: 3-Methylcyclohexene | collvol = 6 | collvolpages = 769 | volume = 56 | pages = 101 | year = 1977 | prep = cv6p0769 }}</ref> When ]s are reduced using LAH, the reagent attacks the less ] end of the epoxide, usually producing a secondary or tertiary alcohol. ]s are reduced to give axial alcohols preferentially.<ref>{{cite journal | last1 = Rickborn | first1 = B. | last2 = Quartucci | first2 = J. | title = Stereochemistry and Mechanism of Lithium Aluminum Hydride and Mixed Hydride Reduction of 4-''t''-Butylcyclohexene Oxide | journal = The Journal of Organic Chemistry | year = 1964 | volume = 29 | issue = 11 | pages = 3185–3188 | doi = 10.1021/jo01034a015 }}</ref>
	==Applications==
	===Use in organic chemistry===
	Lithium aluminium hydride is widely used in organic chemistry as a ].<ref name=africa/> It is more powerful than the related ] ] due to the weaker Al-H bond compared to the B-H bond.<ref>{{cite journal|author=Brown, H. C. |journal=Org. React.|year=1951|volume=6|page=469}}</ref> Often as a solution in ] and followed by an acid work-up, it will convert ]s, ]s, ], and ]s into the corresponding ]s (see: ]). Similarly, it converts ], ], ], ], ], and ] compounds into the ]s (see: ]). It reduces ]s into the corresponding tertiary amines. Reactivity can be tuned by replacing hydride groups ]. Despite handling problems associated with its reactivity, it is even used at the small-industrial scale, although for large-scale reductions, the related reagent ] is more commonly used.<ref>{{Cite web|url=http://www.organic-chemistry.org/chemicals/reductions/sodiumbis(2-methoxyethoxy)aluminumhydride-red-al.shtm|title=Red-Al, Sodium bis(2-methoxyethoxy)aluminumhydride}}</ref>
			Partial reduction of ]s to give the corresponding aldehyde product cannot proceed via LAH, since the latter reduces all the way to the primary alcohol. Instead, the milder ], which reacts significantly faster with the acid chloride than with the aldehyde, must be used. For example, when ] is treated with ] to give isovaleroyl chloride, it can then be reduced via lithium tri-''tert''-butoxyaluminum hydride to give isovaleraldehyde in 65% yield.<ref>{{cite book | author = Wade, L. G. Jr. | title = Organic Chemistry | edition = 6th | publisher = Pearson Prentice Hall | year = 2006 | isbn = 0-13-147871-0 }}</ref><ref>{{cite book |last1=Wade |first1=L. G. |title=Organic chemistry |date=2013 |publisher=Pearson |location=Boston |isbn=978-0-321-81139-4 |pages=835 |edition=8th}}</ref>
	LAH is most commonly used for the reduction of ]s<ref>Reetz, M. T.; Drewes, M. W.; Schwickardi, R. '']'', Coll. Vol. 10, p.256 (2004); Vol. 76, p.110 (1999). ()</ref><ref>Oi, R.; ] '']'', Coll. Vol. 9, p.251 (1998); Vol. 73, p.1 (1996). ()</ref> and ]s<ref>Koppenhoefer, B.; Schurig, V. '']'', Coll. Vol. 8, p.434 (1993); Vol. 66, p.160 (1988). ()</ref> to primary alcohols; prior to the advent of LiAlH<sub>4</sub>, this was a difficult conversion involving ] metal in boiling ] (the ]). ]s and ]s<ref>Barnier, J. P.; Champion, J.; Conia, J. M. '']'', Coll. Vol. 7, p.129 (1990); Vol. 60, p.25 (1981). ()</ref> can also be reduced to alcohols by LAH, but this is usually done using milder reagents such as ]; α,β-unsaturated ketones are reduced to allylic alcohols.<ref>Elphimoff-Felkin, I.; Sarda, P. '']'', Coll. Vol. 6, p.769 (1988); Vol. 56, p.101 (1977). ()</ref> When ]s are reduced using LAH, the reagent attacks the less ] end of the epoxide, usually producing a secondary or tertiary alcohol. Epoxycyclohexanes are reduced to give axial alcohols preferentially.<ref>{{cite journal|doi=10.1021/jo01034a015|title=Stereochemistry and Mechanism of Lithium Aluminum Hydride and Mixed Hydride Reduction of 4-t-Butylcyclohexene Oxide|year=1964|last1=Rickborn|first1=Bruce|last2=Quartucci|first2=Joe|journal=The Journal of Organic Chemistry|volume=29|pages=3185|issue=11}}</ref>
	Partial reduction of ]s to give the corresponding aldehyde product cannot proceed via LAH, since the latter reduces all the way to the primary alcohol. Instead, the milder ] must be used, which reacts significantly faster with the acid chloride than with the aldehyde. For example, when ] is treated with ] to give isovaleroyl chloride, it can then be reduced via lithium aluminium tri(t-butoxy)hydride to give isovaleraldehyde in 65% yield.<ref>Wade, L. G. Jr., ''Organic Chemistry'', 6th edition (Pearson Prentice Hall, 2006, ISBN 0-13-147871-0)</ref>
	<imagemap>		<imagemap>
	Image:LAH_rxns.png|		File:LAH rxns.png|
			rect 5 12 91 74 ]
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	rect 82 178 170 240 ]		rect 82 178 170 240 ]
	rect 121 9 193 69 ]		rect 121 9 193 69 ]
	rect 337 1 414 60 ]		rect 337 1 414 60 ]
	rect 458 55 526 117 ]		rect 458 55 526 117 ]
	rect 170 151 234 210 ]		rect 170 151 234 210 ]
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	rect 135 281 196 300 ]		rect 135 281 196 300 ]
	rect 128 311 204 366 ]		rect 128 311 204 366 ]1
	rect 264 268 339 334 ]		rect 264 268 339 334 ]
	rect 457 362 529 413 ]		rect 457 362 529 413 ]
	rect 381 255 433 273 ]		rect 381 255 433 273 ]
	rect 469 244 525 269 ]		rect 469 244 525 269 ]2
	rect 321 193 401 242 ]		rect 321 193 401 242 ]
	rect 261 141 320 203 ]		rect 261 141 320 203 ]
	desc none		desc none
	#Notes:		#Notes:
	#Details on the new coding for clickable images is here: ]		#Details on the new coding for clickable images is here: ]
	# was used.		# was used.
	</imagemap>		</imagemap>
			Lithium aluminium hydride also reduces ]s to ]s.<ref>{{cite journal | last1 = Johnson | first1 = J. E. | last2 = Blizzard | first2 = R. H. | last3 = Carhart | first3 = H. W. | title = Hydrogenolysis of Alkyl Halides by Lithium Aluminum Hydride | journal = Journal of the American Chemical Society | year = 1948 | volume = 70 | issue = 11 | pages = 3664–3665 | pmid = 18121883 | doi = 10.1021/ja01191a035 }}</ref><ref>{{cite journal | last1 = Krishnamurthy | first1 = S. | last2 = Brown | first2 = H. C. | title = Selective Reductions. 28. The Fast Reaction of Lithium Aluminum Hydride with Alkyl Halides in THF. A Reappraisal of the Scope of the Reaction | journal = The Journal of Organic Chemistry | year = 1982 | volume = 47 | issue = 2 | pages = 276–280 | doi = 10.1021/jo00341a018 }}</ref> Alkyl iodides react the fastest, followed by alkyl bromides and then alkyl chlorides. Primary halides are the most reactive followed by secondary halides. Tertiary halides react only in certain cases.<ref>{{cite book | author = Carruthers, W. | title = Some Modern Methods of Organic Synthesis | publisher = Cambridge University Press | year = 2004 | page = 470 | isbn = 0-521-31117-9 | url = https://books.google.com/books?id=ti7yMYYW7CMC&pg=PA470 }}</ref>
	Using LAH, ]s can be prepared by the reduction of ]s,<ref>Seebach, D.; Kalinowski, H.-O.; Langer, W.; Crass, G.; Wilka, E.-M. '']'', Coll. Vol. 7, p.41 (1990). ()</ref><ref>Park, C. H.; Simmons, H. E. '']'', Coll. Vol. 6, p.382 (1988); Vol. 54, p.88 (1974). ()</ref> ]s,<ref>Chen, Y. K.; Jeon, S.-J.; Walsh, P. J.; Nugent, W. A. '']'', Vol. 82, p.87 (2005). ()</ref> ]s, nitro compounds or alkyl ]s.
			Lithium aluminium hydride does not reduce simple ]s or ]s. ]s are reduced only if an alcohol group is nearby,<ref>{{OrgSynth |author1=Wender, P. A.|author2=Holt, D. A.|author3=Sieburth, S. Mc N.|author3-link=Scott Sieburth | title = 2-Alkenyl Carbinols from 2-Halo Ketones: 2-E-Propenylcyclohexanol | collvol = 7 | collvolpages = 456 | volume = 64 | pages = 10 | year = 1986 | prep = cv7p0456 }}</ref> and alkenes are reduced in the presence of catalytic ].<ref>Brendel, G. (May 11, 1981) "Hydride reducing agents" (letter to the editor) in ''Chemical and Engineering News''. {{doi|10.1021/cen-v059n019.p002|doi-access=free}}</ref> It was observed that the {{chem2|LiAlH4}} reduces the double bond in the ''N''-allylamides.<ref>{{Cite journal|title=Reduction of N-allylamides by LiAlH<sub>4</sub>: Unexpected Attack of the Double Bond With Mechanistic Studies of Product and Byproduct Formation|year = 2014|pmid = 25347383|last1 = Thiedemann|first1 = B.|last2 = Schmitz|first2 = C. M.|last3 = Staubitz|first3 = A.|journal = The Journal of Organic Chemistry|volume = 79|issue = 21|pages = 10284–95|doi = 10.1021/jo501907v}}</ref>
	Lithium aluminium hydride also reduces ]s to ]s, although this reaction is rarely employed.<ref>{{cite journal|doi=10.1021/ja01191a035|year=1948|last1=Johnson|first1=J. Enoch|last2=Blizzard|first2=Ronald H.|last3=Carhart|first3=Homer W.|journal=Journal of the American Chemical Society|volume=70|pages=3664|pmid=18121883|title=Hydrogenolysis of alkyl halides by lithium aluminum hydride|issue=11}}</ref><ref>{{cite journal|doi=10.1021/jo00341a018|title=Selective reductions. 28. The fast reaction of lithium aluminum hydride with alkyl halides in THF. A reappraisal of the scope of the reaction|year=1982|last1=Krishnamurthy|first1=S.|last2=Brown|first2=Herbert C.|journal=The Journal of Organic Chemistry|volume=47|pages=276|issue=2}}</ref> Alkyl iodides react the fastest, followed by alkyl bromides and then alkyl chlorides. Primary halides are the most reactive followed by secondary halides. Tertiary halides react only in certain cases.<ref>{{Cite book|url=http://books.google.com/?id=ti7yMYYW7CMC&pg=PA470|page=470|title=Some modern methods of organic synthesis|author=Carruthers, W.|publisher=Cambridge University Press|year=2004|isbn=0521311179}}</ref>
			=== Inorganic chemistry ===
	Lithium aluminium hydride does not reduce simple ]s, ]s, and ]s are only reduced if an alcohol group is nearby.<ref>Wender, P. A.; Holt, D. A.; Sieburth, S. Mc N. '']'', Coll. Vol. 7, p.456 (1990); Vol. 64, p.10 (1986). ()</ref>
			LAH is widely used to prepare main group and transition ] from the corresponding metal ]s.
			:
	===Inorganic chemistry===
	LAH is widely used to prepare main group and transition ] from the corresponding metal ]s. For example, sodium hydride (NaH) can be prepared from sodium chloride (NaCl) through the following reaction:<ref name="InorganicHandbook">{{cite book|last=Patnaik|first=Pradyot|title=Handbook of Inorganic Chemicals|publisher=McGraw-Hill|year=2003|page=492|isbn=978-0-07-049439-8}}</ref>
	:LiAlH<sub>4</sub> + 4 NaCl → 4 NaH + LiCl + AlCl<sub>3</sub>
	LAH also reacts with many inorganic ligands to form coordinated alumina complexes associated with lithium ions.<ref name="InorganicHandbook" />		LAH also reacts with many inorganic ligands to form coordinated alumina complexes associated with lithium ions.<ref name="InorganicHandbook" />
	:LiAlH<sub>4</sub> + NH<sub>3</sub> → Li		:LiAlH<sub>4</sub> + 4NH<sub>3</sub> → Li + 4H<sub>2</sub>
	===Hydrogen storage===		=== Hydrogen storage ===
	[[File:volvsgrav.png|300px|thumb|Volumetric and gravimetric hydrogen storage densities of different hydrogen storage		[[File:volvsgrav.png|300px|thumb|Volumetric and gravimetric hydrogen storage densities of different hydrogen storage
	methods. Metal hydrides are represented with squares and complex hydrides with triangles (including LiAlH<sub>4</sub>).		methods. Metal hydrides are represented with squares and complex hydrides with triangles (including LiAlH<sub>4</sub>).
	Reported values for hydrides are excluding tank weight. ] ] targets are including tank weight.]]		Reported values for hydrides are excluding tank weight. ] ] targets are including tank weight.]]
	LiAlH<sub>4</sub> contains 10.6 wt% hydrogen thereby making LAH a potential ] medium for future ] powered ]s. The high hydrogen content, as well as the discovery of reversible hydrogen storage in Ti-doped NaAlH<sub>4</sub>,<ref>{{cite journal|doi=10.1016/S0925-8388(96)03049-6|year=1997|last1=Bogdanovic|first1=B|last2=Schwickardi|first2=M|journal=Journal of Alloys and Compounds|volume=253-254|pages=1|title=Ti-doped alkali metal aluminium hydrides as potential novel reversible hydrogen storage materials}}</ref> have sparked renewed research into LiAlH<sub>4</sub> during the last decade. A substantial research effort has been devoted to accelerating the decomposition kinetics by catalytic doping and by ]ing.<ref name="varin">{{cite book|last1=Varin|first1=R A|last2=Czujko|first2=T|last3=Wronski|first3=Z S|title=Nanomaterials for Solid State Hydrogen Storage|publisher=Springer|year=2009|edition=5th|pages=338|isbn=978-0-387-77711-5}}</ref>		LiAlH<sub>4</sub> contains 10.6 wt% hydrogen, thereby making LAH a potential ] medium for future ]-powered ]s. The high hydrogen content, as well as the discovery of reversible hydrogen storage in Ti-doped NaAlH<sub>4</sub>,<ref>{{cite journal | last1 = Bogdanovic | first1 = B. | last2 = Schwickardi | first2 = M. | title = Ti-Doped Alkali Metal Aluminium Hydrides as Potential Novel Reversible Hydrogen Storage Materials | journal = Journal of Alloys and Compounds | year = 1997 | volume = 253–254 | pages = 1–9 | doi = 10.1016/S0925-8388(96)03049-6 }}</ref> have sparked renewed research into LiAlH<sub>4</sub> during the last decade. A substantial research effort has been devoted to accelerating the decomposition kinetics by catalytic doping and by ]ing.<ref name="varin">{{cite book | last1 = Varin | first1 = R. A. |author-link1=Robert A. Varin| last2 = Czujko | first2 = T. | last3 = Wronski | first3 = Z. S. | title = Nanomaterials for Solid State Hydrogen Storage | edition = 5th | year = 2009 | pages = 338 | publisher = Springer | isbn = 978-0-387-77711-5 }}</ref>
	In order to take advantage of the total hydrogen capacity, the intermediate compound ] must be dehydrogenated as well. Due to its high thermodynamic stability this requires temperatures in excess of 400 °C which is not considered feasible for transportation purposes. Accepting LiH + Al as the final product, the hydrogen storage capacity is reduced to 7.96 wt%. Another problem related to hydrogen storage is the recycling back to LiAlH<sub>4</sub> which, due to its relatively low stability, requires an extremely high hydrogen pressure in excess of 10000 bar.<ref name="varin"/> Cycling only reaction R2, that is using Li<sub>3</sub>AlH<sub>6</sub> as starting material, would store 5.6 wt% hydrogen in a single step (vs. two steps for NaAlH<sub>4</sub> which stores about the same amount of hydrogen). However, attempts on this have not been successful so far.		In order to take advantage of the total hydrogen capacity, the intermediate compound ] must be dehydrogenated as well. Due to its high thermodynamic stability this requires temperatures in excess of 400&nbsp;°C, which is not considered feasible for transportation purposes. Accepting LiH + Al as the final product, the hydrogen storage capacity is reduced to 7.96 wt%. Another problem related to hydrogen storage is the recycling back to LiAlH<sub>4</sub> which, owing to its relatively low stability, requires an extremely high hydrogen pressure in excess of 10000 bar.<ref name="varin" /> Cycling only reaction R2 — that is, using Li<sub>3</sub>AlH<sub>6</sub> as starting material — would store 5.6 wt% hydrogen in a single step (vs. two steps for NaAlH<sub>4</sub> which stores about the same amount of hydrogen). However, attempts at this process have not been successful so far.{{citation needed|date=March 2016}}
	===Other tetrahydridoaluminiumates===		=== Other tetrahydridoaluminiumates ===
	A variety of salts analogous to LAH are known. ] can be used to efficiently produce ] (NaAlH<sub>4</sub>) by ] in THF:		A variety of salts analogous to LAH are known. ] can be used to efficiently produce ] (NaAlH<sub>4</sub>) by ] in THF:
	:LiAlH<sub>4</sub> + NaH → NaAlH<sub>4</sub> + LiH		:LiAlH<sub>4</sub> + NaH → NaAlH<sub>4</sub> + LiH
	] (KAlH<sub>4</sub>) can be produced similarly in ] as a solvent:<ref name=react>{{cite journal|doi=10.1016/j.ica.2007.04.044|title=Synthesis of alkali metal hexahydroaluminate complexes using dimethyl ether as a reaction medium|year=2008|last1=Santhanam|first1=Ranganathan|last2=Sean Mcgrady|first2=G.|journal=Inorganica Chimica Acta|volume=361|pages=473|issue=2}}</ref>		] (KAlH<sub>4</sub>) can be produced similarly in ] as a solvent:<ref name=react>{{cite journal | last1 = Santhanam | first1 = R. | last2 = McGrady | first2 = G. S. | title = Synthesis of Alkali Metal Hexahydroaluminate Complexes Using Dimethyl Ether as a Reaction Medium | journal = Inorganica Chimica Acta | year = 2008 | volume = 361 | issue = 2 | pages = 473–478 | doi = 10.1016/j.ica.2007.04.044 }}</ref>
	:LiAlH<sub>4</sub> + KH → KAlH<sub>4</sub> + LiH		:LiAlH<sub>4</sub> + KH → KAlH<sub>4</sub> + LiH
	The reverse, i.e., production of LAH from either sodium aluminium hydride or potassium aluminium hydride can be achieved by reaction with ] or lithium hydride in ] or ]:<ref name=react/>		The reverse, i.e., production of LAH from either sodium aluminium hydride or potassium aluminium hydride can be achieved by reaction with ] or lithium hydride in ] or ]:<ref name="react" />
	:NaAlH<sub>4</sub> + LiCl → LiAlH<sub>4</sub> + NaCl		:NaAlH<sub>4</sub> + LiCl → LiAlH<sub>4</sub> + NaCl
	:KAlH<sub>4</sub> + LiCl → LiAlH<sub>4</sub> + KCl		:KAlH<sub>4</sub> + LiCl → LiAlH<sub>4</sub> + KCl
	"Magnesium alanate" (Mg(AlH<sub>4</sub>)<sub>2</sub>) arises similarly using ]:<ref>{{cite book|url=http://books.google.com/?id=vEwj1WZKThEC&pg=PA1056|page=1056|title=Inorganic chemistry|author=Wiberg, Egon; Wiberg, Nils and Holleman, Arnold Frederick|publisher=Academic Press|year=2001|isbn=0123526515}}</ref>		"Magnesium alanate" (Mg(AlH<sub>4</sub>)<sub>2</sub>) arises similarly using ]:<ref>{{cite book |author1=Wiberg, E. |author2=Wiberg, N. |author3=Holleman, A. F. | title = Inorganic Chemistry | year = 2001 | page = 1056 | publisher = Academic Press | isbn = 0-12-352651-5 | url = https://books.google.com/books?id=vEwj1WZKThEC&pg=PA1056 }}</ref>
	:2 LiAlH<sub>4</sub> + MgBr<sub>2</sub> → Mg(AlH<sub>4</sub>)<sub>2</sub> + 2 LiBr		:2 LiAlH<sub>4</sub> + MgBr<sub>2</sub> → Mg(AlH<sub>4</sub>)<sub>2</sub> + 2 LiBr
	] (or SMEAH, NaAlH<sub>2</sub>(OC<sub>2</sub>H<sub>4</sub>OCH<sub>3</sub>)<sub>2</sub>) is synthesized by reacting sodium aluminum tetrahydride (NaAlH<sub>4</sub>) and ]:<ref>{{cite journal|author=Casensky, B.; Machacek, J.; Abrham, K. |journal=Collect. Czech. Chem. Commun.|year=1971|volume=36|page=2648}}</ref>		] (or SMEAH, NaAlH<sub>2</sub>(OC<sub>2</sub>H<sub>4</sub>OCH<sub>3</sub>)<sub>2</sub>) is synthesized by reacting sodium aluminum tetrahydride (NaAlH<sub>4</sub>) and ]:<ref>{{cite journal |author1=Casensky, B. |title=The chemistry of sodium alkoxyaluminium hydrides. I. Synthesis of sodium bis(2-methoxyethoxy)aluminium hydride |author2=Machacek, J. |author3=Abraham, K. | journal = Collection of Czechoslovak Chemical Communications | year = 1971 | volume = 36 |issue=7 | pages = 2648–2657 |doi=10.1135/cccc19712648 }}</ref>
	==See also==		== See also ==
	{{commons category|lithium aluminium hydride}}		{{Commons category|Lithium aluminium hydride|lcfirst=yes}}
	*]		*]
	*]		*]
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	==References==		== References ==
	{{Reflist|2}}		{{Reflist}}
	==Further reading==		== Further reading ==
	*{{cite book|author=Wiberg, Egon & Amberger, Eberhard|title=Hydrides of the elements of main groups I-IV|publisher=Elsevier|year=1971|isbn=0-444-40807-X}}		*{{cite book |author1=Wiberg, E. |author2=Amberger, E. | title = Hydrides of the Elements of Main Groups I-IV | publisher = Elsevier | year = 1971 | isbn = 0-444-40807-X }}
	*{{cite book|author=Hajos, Andor|title=Complex Hydrides and Related Reducing Agents in Organic Synthesis|publisher=Elsevier|year=1979|isbn=0-444-99791-1}}		*{{cite book | author = Hajos, A. | title = Complex Hydrides and Related Reducing Agents in Organic Synthesis | publisher = Elsevier | year = 1979 | isbn = 0-444-99791-1 }}
	*{{cite book|author=Lide (ed.), David R.|title=Handbook of chemistry and physics|publisher=CRC Press|year=1997|isbn=0-8493-0478-4}}		*{{cite book | editor = Lide, D. R. | title = Handbook of Chemistry and Physics | publisher = CRC Press | year = 1997 | isbn = 0-8493-0478-4 }}
	*{{cite book|author=Carey, Francis A.|title=Organic Chemistry with Online Learning Center and Learning by Model CD-ROM|publisher= McGraw-Hill|year=2002|isbn=0-07-252170-8}}		*{{cite book | author = Carey, F. A. | title = Organic Chemistry with Online Learning Center and Learning by Model CD-ROM | publisher = McGraw-Hill | year = 2002 | isbn = 0-07-252170-8 | url = http://www.chem.ucalgary.ca/courses/351/Carey5th/Carey.html }}
	*Chapter 5 in {{cite book|author=Andreasen, Anders|title=Hydrogen Storage Materials with Focus on Main Group I-II Elements|publisher=Risoe National Laboratory|year=2005|isbn=87-550-3498-5}}		*{{cite book | author = Andreasen, A. | title = Hydrogen Storage Materials with Focus on Main Group I-II Elements | chapter = Chapter 5: Complex Hydrides | publisher = Risø National Laboratory | year = 2005 | isbn = 87-550-3498-5 | chapter-url = http://www.risoe.dk/rispubl/AFM/afmpdf/ris-phd-21.pdf | url-status = dead | archive-url = https://web.archive.org/web/20120819163021/http://www.risoe.dk/rispubl/AFM/afmpdf/ris-phd-21.pdf | archive-date = 2012-08-19 }}
	==External links==		== External links ==
	{{Wiktionary}}		{{Wiktionary}}
	*Usage of LiAlH<sub>4</sub> in		*{{cite web | title = Usage of LiAlH<sub>4</sub> | url = http://www.orgsyn.org/orgsyn/chemname.asp?nameID=36257 | publisher = Organic Syntheses }}
			*{{cite web | url = https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=28112 | publisher = PubChem | title = Lithium Tetrahydridoaluminate – Compound Summary (CID 28112) }}
	*
			*{{cite web | url = http://webbook.nist.gov/cgi/cbook.cgi?Formula=LiAlH4&NoIon=on&Units=SI | title = Lithium Tetrahydridoaluminate | publisher = NIST | work = WebBook }}
	*
			*{{cite web|url=http://msds.ehs.cornell.edu/msds/MSDSDOD/A441/M220131.htm |title=Materials Safety Data Sheet |publisher=Cornell University |url-status=dead |archive-url=https://web.archive.org/web/20060308045012/http://msds.ehs.cornell.edu/msds/MSDSDOD/A441/M220131.htm |archive-date=March 8, 2006 }}
	*
			*{{cite web|url=http://hydpark.ca.sandia.gov/ |publisher=Sandia National Laboratory |title=Hydride Information Center |url-status=dead |archive-url=https://web.archive.org/web/20050507175350/http://hydpark.ca.sandia.gov/ |archive-date=May 7, 2005 }}
	*
	*		*{{cite web|url=http://www.chem2.bham.ac.uk/labs/cox/Teaching/4th_Year/II/Reduction_Reactions.pdf |archive-url=http://arquivo.pt/wayback/20160523233903/http://www.chem2.bham.ac.uk/labs/cox/Teaching/4th_Year/II/Reduction_Reactions.pdf |url-status=dead |archive-date=May 23, 2016 |title=Reduction Reactions |publisher=University of Birmingham |work=Teaching Resources – 4th Year }}
	*
	{{Lithium compounds}}		{{Lithium compounds}}
			{{aluminium compounds}}
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