Lithium aluminium hydride

File:Lialh4 sem.png image of LAH powder]]

LAH is a colourless solid but commercial samples are usually gray due to contamination.{{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 }} This material can be purified by recrystallization from diethyl ether. Large-scale purifications employ a Soxhlet extractor. 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 pyrophoric, but not its large crystals.{{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 = [https://archive.org/details/practicalorganic0000kees/page/134 134] | isbn = 0-470-02966-8 | url = https://archive.org/details/practicalorganic0000kees |url-access=registration }} Some commercial materials contain mineral oil to inhibit reactions with atmospheric moisture, but more commonly it is packed in moisture-proof plastic sacks.{{cite journal | last1 = Andreasen | first1 = A. | last2 = Vegge | first2 = T. | last3 = Pedersen | first3 = A. S. | title = Dehydrogenation Kinetics of as-Received and Ball-Milled LiAlH₄ | 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 }}

LAH violently reacts with water, including atmospheric moisture, to liberate hydrogen gas. The reaction proceeds according to the following idealized equation:

:{{chem2|Li[AlH4] + 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 lithium hydroxide and aluminium hydroxide.{{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 }}

File:Lithium-aluminium-hydride-unit-cell-3D-polyhedra.png

LAH crystallizes in the monoclinic space group P2₁/c. The unit cell 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+}} cations are surrounded by five {{chem2|[AlH4]−}} anions, which have tetrahedral molecular geometry. The {{chem2|Li+}} cations are bonded to one hydrogen atom from each of the surrounding tetrahedral {{chem2|[AlH4]−}} anion creating a bipyramid arrangement. At high pressures (>2.2 GPa) a phase transition may occur to give β-LAH.{{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 LiAlH₄ and Li₃AlH₆ | journal = Physical Review B | year = 2004 | volume = 69 | issue = 13 | pages = 134117 | doi = 10.1103/PhysRevB.69.134117 |bibcode=2004PhRvB..69m4117L }}

File:Lialh4 xrpd.svg pattern of as-received {{chem2|Li[AlH4]}}. The asterisk designates an impurity, possibly LiCl.]]

{{chem2|Li[AlH4]}} was first prepared from the reaction between lithium hydride (LiH) and aluminium chloride:

:{{chem2|4 LiH + AlCl3 → Li[AlH4] + 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:{{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 }}

:{{chem2|Na + Al + 2 H2 → Na[AlH4]}}

{{chem2|Li[AlH4]}} is then prepared by a salt metathesis reaction according to:

:{{chem2|Na[AlH4] + LiCl → Li[AlH4] + NaCl}}

which proceeds in a high yield. LiCl is removed by filtration from an ethereal solution of LAH, with subsequent precipitation of LAH to yield a product containing around 1 wt% LiCl.

An alternative preparation starts from LiH, and metallic Al instead of {{chem2|AlCl3}}. Catalyzed by a small quantity of TiCl₃ (0.2%), the reaction proceeds well using dimethylether as solvent. This method avoids the cogeneration of salt.{{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 LiAlH₄ 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 }}

LAH is soluble in many ethereal solutions. However, it may spontaneously decompose due to the presence of catalytic impurities, though, it appears to be more stable in tetrahydrofuran (THF). Thus, THF is preferred over, e.g., diethyl ether, despite the lower solubility.

LAH is metastable at room temperature. During prolonged storage it slowly decomposes to {{chem2|Li3[AlH6]}} (lithium hexahydridoaluminate) and LiH.{{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 }} This process can be accelerated by the presence of catalytic elements, such as titanium, iron or vanadium.

File:Lialh4 dsc.svg of as-received {{chem2|Li[AlH4]}}.]]

When heated LAH decomposes in a three-step reaction mechanism:{{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 }}{{cite journal | last1 = Blanchard | first1 = D. | last2 = Brinks | first2 = H. | last3 = Hauback | first3 = B. | last4 = Norby | first4 = P. | title = Desorption of LiAlH₄ 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 }}

{{NumBlk|:|{{chem2|3 Li[AlH4] → Li3[AlH6] + 2 Al + 3 H2}} |{{EquationRef|R1}}}}

{{NumBlk|:|{{chem2|2 Li3[AlH6] → 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 melting of LAH in the temperature range 150–170 °C,{{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 LiAlH₄ and Li₃AlH₆ | journal = The Journal of Physical Chemistry B | year = 2001 | volume = 105 | issue = 45 | pages = 11214–11220 | doi = 10.1021/jp012127w }}{{cite journal | last1 = Balema | first1 = V. | last2 = Pecharsky | first2 = V. K. | last3 = Dennis | first3 = K. W. | title = Solid State Phase Transformations in LiAlH₄ 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 }}{{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 }} immediately followed by decomposition into solid {{chem2|Li3[AlH6]}}, although {{EquationNote|R1}} is known to proceed below the melting point of {{chem2|Li[AlH4]}} as well.{{cite journal | last1 = Andreasen | first1 = A. | last2 = Pedersen | first2 = A. S. | last3 = Vegge | first3 = T. | title = Dehydrogenation Kinetics of as-Received and Ball-Milled LiAlH₄ | 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 }} At about 200 °C, {{chem2|Li3[AlH6]}} decomposes into LiH ({{EquationNote|R2}}) and Al which subsequently convert into LiAl above 400 °C ({{EquationNote|R3}}). Reaction R1 is effectively irreversible. {{EquationNote|R3}} is reversible with an equilibrium pressure of about 0.25 bar at 500 °C. {{EquationNote|R1}} and {{EquationNote|R2}} can occur at room temperature with suitable catalysts.{{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 LiAlH₄ 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 }}

The table summarizes thermodynamic data for LAH and reactions involving LAH,{{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=[https://archive.org/details/Handbook_of_Inorganic_Chemistry_Patnaik/page/n530 492]}}{{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 }} in the form of standard enthalpy, entropy, and Gibbs free energy change, respectively.

Lithium aluminium hydride (LAH) is widely used in organic chemistry as a reducing agent. It is more powerful than the related reagent sodium borohydride owing to the weaker Al-H bond compared to the B-H bond.{{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 }} Often as a solution in diethyl ether and followed by an acid workup, it will convert esters, carboxylic acids, acyl chlorides, aldehydes, and ketones into the corresponding alcohols (see: carbonyl reduction). Similarly, it converts amide,{{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 }}{{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 }} nitro, nitrile, imine, oxime,{{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 }} and organic azides into the amines (see: amide reduction). It reduces quaternary ammonium cations into the corresponding tertiary amines. Reactivity can be tuned by replacing hydride groups by alkoxy 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 sodium bis (2-methoxyethoxy)aluminium hydride, which exhibits similar reactivity but with higher safety, easier handling and better economics.{{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 }}

LAH is most commonly used for the reduction of esters{{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 }}{{OrgSynth |author1=Oi, R.|author2=Sharpless, K. B. | title = 3-[(1S)-1,2-Dihydroxyethyl]-1,5-Dihydro-3H-2,4-Benzodioxepine | collvol = 9 | collvolpages = 251 | volume = 73 | pages = 1 | year = 1996 | prep = cv9p0251 }} and carboxylic acids{{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 }} to primary alcohols; prior to the advent of LAH this was a difficult conversion involving sodium metal in boiling ethanol (the Bouveault-Blanc reduction). Aldehydes and ketones{{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 }} can also be reduced to alcohols by LAH, but this is usually done using milder reagents such as sodium borohydride; α, β-unsaturated ketones are reduced to allylic alcohols.{{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 }} When epoxides are reduced using LAH, the reagent attacks the less hindered end of the epoxide, usually producing a secondary or tertiary alcohol. Epoxycyclohexanes are reduced to give axial alcohols preferentially.{{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 }}

Partial reduction of acid chlorides to give the corresponding aldehyde product cannot proceed via LAH, since the latter reduces all the way to the primary alcohol. Instead, the milder lithium tri-tert-butoxyaluminum hydride, which reacts significantly faster with the acid chloride than with the aldehyde, must be used. For example, when isovaleric acid is treated with thionyl chloride to give isovaleroyl chloride, it can then be reduced via lithium tri-tert-butoxyaluminum hydride to give isovaleraldehyde in 65% yield.{{cite book | author = Wade, L. G. Jr. | title = Organic Chemistry | edition = 6th | publisher = Pearson Prentice Hall | year = 2006 | isbn = 0-13-147871-0 }}{{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}}

File:LAH rxns.png|

rect 5 12 91 74 alcohol

rect 82 178 170 240 epoxide

rect 121 9 193 69 alcohol2

rect 337 1 414 60 alcohol3

rect 458 55 526 117 alcohol4

rect 170 151 234 210 aldehyde

rect 141 259 207 279 nitrile

rect 135 281 196 300 amide

rect 128 311 204 366 amine1

rect 264 268 339 334 carboxylic acid

rect 457 362 529 413 alcohol5

rect 381 255 433 273 azide

rect 469 244 525 269 amine2

rect 321 193 401 242 ester

rect 261 141 320 203 ketone

desc none

1. Notes:
2. Details on the new coding for clickable images is here: mw:Extension:ImageMap
3. [https://web.archive.org/web/20080327003154/http://tools.wikimedia.de/~dapete/ImageMapEdit/ImageMapEdit.html?en This image editor] was used.

Lithium aluminium hydride also reduces alkyl halides to alkanes.{{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 }}{{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 }} 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.{{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 }}

Lithium aluminium hydride does not reduce simple alkenes or arenes. Alkynes are reduced only if an alcohol group is nearby,{{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 }} and alkenes are reduced in the presence of catalytic TiCl₄.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}} It was observed that the {{chem2|LiAlH4}} reduces the double bond in the N-allylamides.{{Cite journal|title=Reduction of N-allylamides by LiAlH₄: 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}}

LAH is widely used to prepare main group and transition metal hydrides from the corresponding metal halides.

:

LAH also reacts with many inorganic ligands to form coordinated alumina complexes associated with lithium ions.

:LiAlH₄ + 4NH₃ → Li[Al(NH₂)₄] + 4H₂

[[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 LiAlH₄).

Reported values for hydrides are excluding tank weight. DOE FreedomCAR targets are including tank weight.]]

LiAlH₄ contains 10.6 wt% hydrogen, thereby making LAH a potential hydrogen storage medium for future fuel cell-powered vehicles. The high hydrogen content, as well as the discovery of reversible hydrogen storage in Ti-doped NaAlH₄,{{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 }} have sparked renewed research into LiAlH₄ during the last decade. A substantial research effort has been devoted to accelerating the decomposition kinetics by catalytic doping and by ball milling.{{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 }}

In order to take advantage of the total hydrogen capacity, the intermediate compound LiH 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 LiAlH₄ which, owing to its relatively low stability, requires an extremely high hydrogen pressure in excess of 10000 bar. Cycling only reaction R2 — that is, using Li₃AlH₆ as starting material — would store 5.6 wt% hydrogen in a single step (vs. two steps for NaAlH₄ which stores about the same amount of hydrogen). However, attempts at this process have not been successful so far.{{citation needed|date=March 2016}}

A variety of salts analogous to LAH are known. NaH can be used to efficiently produce sodium aluminium hydride (NaAlH₄) by metathesis in THF:

:LiAlH₄ + NaH → NaAlH₄ + LiH

Potassium aluminium hydride (KAlH₄) can be produced similarly in diglyme as a solvent:{{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 }}

:LiAlH₄ + KH → KAlH₄ + LiH

The reverse, i.e., production of LAH from either sodium aluminium hydride or potassium aluminium hydride can be achieved by reaction with LiCl or lithium hydride in diethyl ether or THF:

:NaAlH₄ + LiCl → LiAlH₄ + NaCl

:KAlH₄ + LiCl → LiAlH₄ + KCl

"Magnesium alanate" (Mg(AlH₄)₂) arises similarly using MgBr₂:{{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 }}

:2 LiAlH₄ + MgBr₂ → Mg(AlH₄)₂ + 2 LiBr

Red-Al (or SMEAH, NaAlH₂(OC₂H₄OCH₃)₂) is synthesized by reacting sodium aluminum tetrahydride (NaAlH₄) and 2-methoxyethanol:{{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 }}

{{Commons category|Lithium aluminium hydride|lcfirst=yes}}

• Hydride
• Sodium borohydride
• Sodium hydride

{{Reflist}}

• {{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, A. | title = Complex Hydrides and Related Reducing Agents in Organic Synthesis | publisher = Elsevier | year = 1979 | isbn = 0-444-99791-1 }}
• {{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, 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 }}
• {{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 }}

{{Wiktionary}}

• {{cite web | title = Usage of LiAlH₄ | 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}}

{{aluminium compounds}}

Category:Lithium compounds

Category:Aluminium complexes

Category:Metal hydrides

Category:Reducing agents

Category:Substances discovered in the 1940s