{"id":17875,"date":"2026-04-19T11:03:31","date_gmt":"2026-04-19T05:33:31","guid":{"rendered":"https:\/\/aluminiummagazine.com\/mag\/?p=17875"},"modified":"2026-04-19T11:03:34","modified_gmt":"2026-04-19T05:33:34","slug":"lithium-aluminum-hydride-lah-synthesis-guide","status":"publish","type":"post","link":"https:\/\/aluminiummagazine.com\/mag\/aluminium\/compounds\/lithium-aluminum-hydride-lah-synthesis-guide.html","title":{"rendered":"Lithium Aluminum Hydride (LiAlH\u2084): The Complete Guide"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Lithium aluminum hydride, commonly abbreviated as <strong>LAH<\/strong>, is a complex ionic salt (<strong>Li\u207a AlH\u2084\u207b<\/strong>) and one of the most powerful reducing agents used in organic chemistry. It appears as a white to gray microcrystalline powder. Due to its extreme reactivity with water and air, LAH must be handled under strictly inert conditions to prevent fires and explosions.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">1. <strong>Basic Identification<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Chemical Formula:<\/strong> LiAlH\u2084<\/li>\n\n\n\n<li><strong>Alternative Names:<\/strong> LAH, Lithal, lithium tetrahydridoaluminate<\/li>\n\n\n\n<li><strong>Molecular Weight:<\/strong> 37.95 g\/mol<\/li>\n\n\n\n<li><strong>CAS Number:<\/strong> 16853-85-3<\/li>\n\n\n\n<li><strong>Appearance:<\/strong> White powder (pure) or gray (commercial, due to trace aluminum metal)<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">2. <strong>Physical Properties<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-center\" data-align=\"center\">Property<\/th><th class=\"has-text-align-center\" data-align=\"center\">Lithium Aluminum Hydride<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Melting Point<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">~150\u202f\u00b0C (decomposes while melting)<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Boiling Point<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Decomposes before boiling<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Density<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">0.917 g\/cm\u00b3 (very light, floats on water \u2013 but never allow contact)<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Solubility<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Soluble in dry diethyl ether and tetrahydrofuran (THF); violently reacts with water and alcohols<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">LAH is a fluffy, lightweight powder. It is typically purchased in sealed cans or as a solution in THF.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">3. <strong>Chemical Behavior &amp; Reactions<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">3.1 Powerful Reducing Agent<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">LAH delivers hydride ions (H\u207b) to electron\u2011deficient carbon atoms. It reduces a wide range of functional groups:<\/p><div class=\"pai-ad\" style=\"min-height:250px;visibility:hidden;\"><span style=\"display: block; text-align: center; font-size: 10px; margin: 0 0 10px 0; color: #999999;\">Ads<\/span>\r\n<!-- Display-300x250-1 -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:inline-block;width:300px;height:250px\"\r\n     data-ad-client=\"ca-pub-3838168351244230\"\r\n     data-ad-slot=\"9933646018\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><\/div>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Carboxylic acids<\/strong> \u2192 primary alcohols<\/li>\n\n\n\n<li><strong>Esters<\/strong> \u2192 primary alcohols<\/li>\n\n\n\n<li><strong>Amides<\/strong> \u2192 amines<\/li>\n\n\n\n<li><strong>Aldehydes and ketones<\/strong> \u2192 primary or secondary alcohols<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">It does <strong>not<\/strong> reduce isolated carbon\u2011carbon double bonds (alkenes) because the negatively charged hydride is repelled by the electron\u2011rich \u03c0 bond.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3.2 Reaction with Water (The Primary Danger)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">LAH reacts violently with water, releasing hydrogen gas and large amounts of heat:<\/p>\n\n\n\n<p class=\"has-large-font-size wp-block-paragraph\"><strong>LiAlH\u2084 + 4 H\u2082O \u2192 LiOH + Al(OH)\u2083 + 4 H\u2082 \u2191<\/strong><\/p><div class=\"pai-ad\" style=\"min-height:250px;visibility:hidden;\"><span style=\"display: block; text-align: center; font-size: 10px; margin: 0 0 10px 0; color: #999999;\">Ads<\/span>\r\n<!-- Display-300x250-1 -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:inline-block;width:300px;height:250px\"\r\n     data-ad-client=\"ca-pub-3838168351244230\"\r\n     data-ad-slot=\"9933646018\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">The heat can ignite the hydrogen, causing a fire or explosion. Even atmospheric humidity will cause the powder to fizz and degrade. Never expose LAH to open air without inert gas protection.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">4. <strong>Applications<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">4.1 Pharmaceutical Synthesis<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">LAH is used to synthesize complex drug molecules where selective, powerful reduction is required. Many life\u2011saving drugs rely on LAH to convert amides to amines or esters to alcohols in the final steps of their synthesis.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4.2 Fragrance and Flavor Chemistry<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">High\u2011value alcohols and volatile esters for perfumes and flavors are often produced using LAH due to its clean reaction profile and high yield.<\/p><div class=\"pai-ad\" style=\"min-height:250px;visibility:hidden;\"><span style=\"display: block; text-align: center; font-size: 10px; margin: 0 0 10px 0; color: #999999;\">Ads<\/span>\r\n<!-- Display-300x250-1 -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:inline-block;width:300px;height:250px\"\r\n     data-ad-client=\"ca-pub-3838168351244230\"\r\n     data-ad-slot=\"9933646018\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">4.3 Polymer Analysis<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">LAH can cleave ester linkages in cross\u2011linked polymers, allowing researchers to analyze polymer structure by breaking them down into monomer units.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">5. <strong>Safety &amp; Hazard Management<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-center\" data-align=\"center\">GHS Symbol<\/th><th class=\"has-text-align-center\" data-align=\"center\">Meaning<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\">\ud83d\udd25 GHS02<\/td><td class=\"has-text-align-center\" data-align=\"center\">Highly flammable<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">\u26a0\ufe0f GHS05<\/td><td class=\"has-text-align-center\" data-align=\"center\">Water\u2011reactive, corrosive<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">5.1 Health Effects<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Route of Exposure<\/th><th>Effect<\/th><\/tr><\/thead><tbody><tr><td><strong>Inhalation<\/strong><\/td><td>Severe burns to respiratory tract due to reaction with moisture<\/td><\/tr><tr><td><strong>Skin Contact<\/strong><\/td><td>Thermal and caustic burns (reaction with sweat)<\/td><\/tr><tr><td><strong>Eye Contact<\/strong><\/td><td>Catastrophic corneal destruction \u2013 permanent blindness<\/td><\/tr><tr><td><strong>Ingestion<\/strong><\/td><td>Life\u2011threatening; hydrogen gas release and severe internal burns<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">5.2 Personal Protective Equipment (PPE)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Respiratory:<\/strong> All handling of solid LAH must be inside an argon\u2011 or nitrogen\u2011purged glovebox.<\/li>\n\n\n\n<li><strong>Hands:<\/strong> Neoprene gloves inside glovebox.<\/li>\n\n\n\n<li><strong>Eyes:<\/strong> Face shield over tight\u2011seal goggles.<\/li>\n\n\n\n<li><strong>Body:<\/strong> Fire\u2011resistant lab coat (Nomex or similar).<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">5.3 Firefighting Information<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Use:<\/strong> Class D dry powder extinguisher, dry sand, or powdered limestone.<\/li>\n\n\n\n<li><strong>Do NOT use:<\/strong> Water, foam, CO\u2082 (LAH can react with CO\u2082).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">6. <strong>Storage &amp; Handling<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Container:<\/strong> Hermetically sealed glass or metal canisters.<\/li>\n\n\n\n<li><strong>Atmosphere:<\/strong> Under dry argon or nitrogen.<\/li>\n\n\n\n<li><strong>Location:<\/strong> Cool, ventilated flammable\/water\u2011reactive storage, separate from incompatible chemicals.<\/li>\n\n\n\n<li><strong>Incompatibles:<\/strong> Water, alcohols, acids, halocarbons, oxygen, oxidizers.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">6.1 Disposal \u2013 \u201cQuenching\u201d<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Quenching leftover LAH is a hazardous procedure. The standard <strong>Fieser method<\/strong> involves slow, controlled addition of ethyl acetate or a wet solvent to an ice\u2011cooled LAH solution behind a blast shield. Rapid addition can cause explosion. After complete quenching, the neutralized slurry can be disposed as hazardous waste.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">7. <strong>Environmental Impact<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">LAH does not persist in the environment. It reacts violently with moisture, igniting or decomposing rapidly. The residues (lithium and aluminum hydroxides) are alkaline but localized. Large spills require professional hazmat response.<\/p><div class=\"pai-ad\" style=\"min-height:250px;visibility:hidden;\"><span style=\"display: block; text-align: center; font-size: 10px; margin: 0 0 10px 0; color: #999999;\">Ads<\/span>\r\n<!-- Display-300x250-1 -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:inline-block;width:300px;height:250px\"\r\n     data-ad-client=\"ca-pub-3838168351244230\"\r\n     data-ad-slot=\"9933646018\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">8. <strong>Comparison with Other Reducing Agents<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-center\" data-align=\"center\">Agent<\/th><th class=\"has-text-align-center\" data-align=\"center\">Formula<\/th><th class=\"has-text-align-center\" data-align=\"center\">Reducing Power<\/th><th>Reactivity \/ Danger<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Lithium Aluminum Hydride<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">LiAlH\u2084<\/td><td class=\"has-text-align-center\" data-align=\"center\">Extreme<\/td><td>Violently water\u2011reactive, flammable<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Sodium Borohydride<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">NaBH\u2084<\/td><td class=\"has-text-align-center\" data-align=\"center\">Mild<\/td><td>Can be used in water\/alcohol solutions<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Aluminum Hydride<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">AlH\u2083<\/td><td class=\"has-text-align-center\" data-align=\"center\">Very strong<\/td><td>Unstable, experimental rocket fuel<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">9. <strong>Frequently Asked Questions<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q: My LAH is gray instead of white \u2013 is it ruined?<\/strong><br>A: No. Commercial LAH often contains trace aluminum metal, which gives a gray color. It is usually still active. Test with a small reduction if unsure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q: I left a spatula with LAH crust on the bench \u2013 is that safe?<\/strong><br>A: No. Immediately quench the spatula with ethyl acetate or isopropanol in a fume hood. The crust can absorb humidity and ignite nearby flammables.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Q: Why can\u2019t LAH reduce a carbon\u2011carbon double bond?<\/strong><br>A: LAH delivers hydride (H\u207b), a negatively charged species. Carbon\u2011carbon double bonds are electron\u2011rich and repel the hydride, so no reaction occurs.<\/p><div class=\"pai-ad\" style=\"min-height:250px;visibility:hidden;\"><span style=\"display: block; text-align: center; font-size: 10px; margin: 0 0 10px 0; color: #999999;\">Ads<\/span>\r\n<!-- Display-300x250-1 -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:inline-block;width:300px;height:250px\"\r\n     data-ad-client=\"ca-pub-3838168351244230\"\r\n     data-ad-slot=\"9933646018\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<div style=\"height:75px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">10. <strong>Summary Data Sheet<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-center\" data-align=\"center\">Property<\/th><th class=\"has-text-align-center\" data-align=\"center\">Value<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Chemical Name<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Lithium Aluminum Hydride<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Acronym<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">LAH<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Formula<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">LiAlH\u2084<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Appearance<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">White to gray fluffy powder<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Solubility<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Soluble in ether\/THF; explodes in water<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Primary Utility<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Powerful reducing agent in organic synthesis<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Hazard Note<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Violently water\u2011reactive; causes fires<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/p><script>document.addEventListener(\"DOMContentLoaded\",function(){\n        if(window.innerWidth <= 768){\n            if (\"immediate\" === \"delay\") {\n                setTimeout(function(){document.querySelectorAll(\".pai-ad\").forEach(el=>el.style.visibility=\"visible\")},0);\n            } else if (\"immediate\" === \"scroll\") {\n                window.addEventListener(\"scroll\",function(){\n                    let s=window.scrollY\/(document.body.scrollHeight-window.innerHeight);\n                    if(s>0.1){\n                        document.querySelectorAll(\".pai-ad\").forEach(el=>el.style.visibility=\"visible\");\n                    }\n                });\n            } else {\n                document.querySelectorAll(\".pai-ad\").forEach(el=>el.style.visibility=\"visible\");\n            }\n        } else {\n            document.querySelectorAll(\".pai-ad\").forEach(el=>el.remove());\n        }\n    });<\/script>","protected":false},"excerpt":{"rendered":"<p>Lithium aluminum hydride, commonly abbreviated as LAH, is a complex ionic salt (Li\u207a AlH\u2084\u207b) and one of the most powerful reducing agents used in organic chemistry. It appears as a white to gray microcrystalline powder. Due to its extreme reactivity with water and air, LAH must be handled under strictly inert conditions to prevent fires &#8230; <a title=\"Lithium Aluminum Hydride (LiAlH\u2084): The Complete Guide\" class=\"read-more\" href=\"https:\/\/aluminiummagazine.com\/mag\/aluminium\/compounds\/lithium-aluminum-hydride-lah-synthesis-guide.html\" aria-label=\"Read more about Lithium Aluminum Hydride (LiAlH\u2084): The Complete Guide\">Read more<\/a><\/p>\n","protected":false},"author":12,"featured_media":17978,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4155],"tags":[4141,4142],"class_list":["post-17875","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-compounds","tag-aluminium-compounds","tag-aluminum-formula"],"_links":{"self":[{"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/posts\/17875","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/comments?post=17875"}],"version-history":[{"count":0,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/posts\/17875\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/media\/17978"}],"wp:attachment":[{"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/media?parent=17875"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/categories?post=17875"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/tags?post=17875"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}