Thaum nws los txog rau chemical reagents,Lithium Aluminium Hydride(LAH) yog ib lub npe uas feem ntau tshwm sim hauv cov chaw kuaj tshuaj lom neeg. Tab sis koj puas tau xav txog nws cov khoom, tshwj xeeb tshaj yog nws cov hauv paus? Hauv tsab xov xwm no, peb yuav dhia tob rau hauv lub ntiaj teb ntawm cov khoom lag luam thiab tshawb xyuas seb nws puas tuaj yeem raug cais raws li lub hauv paus muaj zog.
nkag siab txog lithium aluminium hydride: qauv thiab cov khoom
Ua ntej peb tackle cov lus nug ntawm lub hauv paus, cia peb xub nkag siab tias cov khoom yog dab tsi thiab nws cov khoom tseem ceeb. Cov khoom, nrog rau cov tshuaj formula LiAlH4, yog ib tug haib txo tus neeg sawv cev dav siv nyob rau hauv cov organic synthesis. Nws yog dawb, crystalline khoom uas reacts hnyav nrog dej, uas yog vim li cas nws feem ntau khaws cia rau hauv cov dej tsis muaj dej.
Cov qauv ntawm cov khoom muaj xws li tetrahedral AlH4-anion balanced los ntawm Li+cation. Cov qauv tshwj xeeb no ua rau nws cov khoom txo qis, ua rau nws mus-rau reagent rau hloov carbonyl tebchaw rau cawv, txo cov carboxylic acids rau thawj cawv, thiab txawm hloov nitriles rau thawj amines.
Tab sis ua li cas txog nws lub hauv paus? Txhawm rau teb qhov no, peb yuav tsum nkag siab txog lub tswv yim ntawm cov hauv paus thiab yuav ua li cas LAH cuam tshuam nrog lwm yam khoom.
Tshawb nrhiav lub hauv paus ntawm lithium aluminium hydride
Hauv chemistry, lub hauv paus feem ntau txhais tau tias yog ib yam khoom uas tuaj yeem txais cov protons (Brønsted-Lowry txhais) lossis pub dawb electron khub (Lewis txhais). Lub hauv paus muaj zog yog cov uas tsis sib haum xeeb hauv cov kev daws teeb meem aqueous, uas ua rau muaj qhov siab ntawm hydroxide ions (OH-).
Thaum peb saib Lithium Aluminium Hydride los ntawm lub lens no, peb pom tias nws tsis haum zoo rau hauv qeb ntawm ib txwm muaj zog hauv paus xws li sodium hydroxide (NaOH) lossis potassium hydroxide (KOH). Txawm li cas los xij, qhov no tsis tau txhais hais tias nws tsis muaj cov khoom tseem ceeb tag nrho.
Qhov tseeb, cov khoom lag luam qhia tus cwj pwm muaj zog hauv qee cov ntsiab lus. Thaum nws hnov mob nrog dej lossis cov kuab tshuaj tiv thaiv, nws ua rau muaj zog aluminium hydroxide thiab lithium hydroxide. Cov tshuaj tiv thaiv tuaj yeem sawv cev raws li:
LiAlH4 + 4H2O → LiOH + Al(OH)3 + 4H2
Cov tshuaj tiv thaiv no yog exothermic heev thiab tuaj yeem ua rau muaj kev phom sij yog tias tsis tswj tau zoo. Qhov tshwm sim hydroxides pab txhawb rau qhov tseem ceeb ntawm cov tshuaj. Txawm li cas los xij, nws tseem ceeb heev uas yuav tsum nco ntsoov tias qhov tseem ceeb no yog los ntawm cov khoom siv tshuaj tiv thaiv ntau dua li LAH nws tus kheej.
lithium aluminium hydride: dhau qhov pib
Thaum cov lus nug ntawm sebLithium Aluminium Hydrideyog lub hauv paus muaj zog tej zaum yuav tsis muaj cov lus teb ncaj nraim, nws qhov tseem ceeb hauv cov organic chemistry nthuav dav dhau qhov kev faib tawm no. Cia peb tshawb txog qee qhov kev siv tseem ceeb thiab cov yam ntxwv ntawm qhov sib xyaw ua ke ntau yam:
Tus neeg saib xyuas muaj zog
LAH feem ntau paub txog nws cov khoom muaj zog txo qis. Nws tuaj yeem txo qis ntau pawg ua haujlwm, suav nrog aldehydes, ketones, carboxylic acids, thiab esters rau lawv cov cawv sib xws.
01
Xaiv qhov txo qis
Qee zaum, cov khoom lag luam tuaj yeem ua cov kev xaiv txo qis, ua rau nws muaj txiaj ntsig zoo hauv cov organic syntheses.
02
Hydrogen Cia
Vim nws cov ntsiab lus hydrogen siab, LAH tau kawm ua cov khoom siv hydrogen muaj peev xwm rau kev siv roj cell.
03
Pyrophoric xwm
Cov khoom yog heev reactive nrog huab cua thiab noo noo, feem ntau igniting spontaneously. Cov cuab yeej no yuav tsum tau ua tib zoo tuav thiab khaws cov txheej txheem.
04
Kev siv Catalytic
Qee qhov xwm txheej, LAH tuaj yeem ua tus catalyst lossis tus thawj coj ntawm cov kab ke catalytic hauv ntau yam tshuaj tiv thaiv.
05
Kev nkag siab txog cov khoom thiab kev siv ntawm cov khoom no yog qhov tseem ceeb rau cov kws kho mob thiab cov kws tshawb fawb ua haujlwm hauv cov organic synthesis, cov ntaub ntawv tshawb fawb, thiab lwm yam. Txawm hais tias nws qhov kev faib tawm raws li lub hauv paus muaj zog tuaj yeem sib cav, nws qhov tseem ceeb hauv ntiaj teb ntawm chemistry yog undeniable.
Kev siv thiab qhov tseem ceeb ntawm lithium aluminium hydride hauv chemistry
Kev nkag siab txog cov khoom tshwj xeeb ntawm nws, suav nrog nws qhov txo qis zog thiab qhov pib me me, pab peb txaus siab rau nws cov kev siv ntau yam hauv chemistry. Cia peb tshawb xyuas qee qhov kev siv tseem ceeb ntawm LAH:
Txo cov pab pawg ua haujlwm
LAH feem ntau yog siv los txo ntau pawg ua haujlwm hauv cov organic tebchaw. Nws tuaj yeem txo cov aldehydes, ketones, carboxylic acids, esters, thiab ntau lwm cov carbonyl-muaj cov tebchaw rau lawv cov cawv sib xws.
01
Synthesis of Primary Alcohols
LAH muaj txiaj ntsig tshwj xeeb hauv kev hloov cov carboxylic acids lossis esters rau hauv cov cawv thawj, kev hloov pauv uas nyuaj nrog lwm cov tshuaj txo qis.
02
Kev tsim tawm ntawm Amines
Nitriles thiab amides tuaj yeem txo qis rau thawj amines siv LAH, ua rau nws muaj txiaj ntsig zoo hauv kev sib xyaw ntawm ntau cov ntsiab lus nitrogen.
03
Txo cov Organometallic Compounds
LAH tuaj yeem txo qee cov tshuaj organometallic, uas yog qhov tseem ceeb hauv kev npaj cov tshuaj reagents tshwj xeeb.
04
Hydrogen Cia
Vim nws cov ntsiab lus hydrogen siab, LAH tau kawm ua cov khoom siv hydrogen muaj peev xwm rau kev siv roj cell.
05
Lub versatility ntawm Lithium Aluminium Hydride nyob rau hauv cov organic synthesis stems los ntawm nws muaj zog txo hwj chim ua ke nrog nws me ntsis yooj yim. Qhov kev sib xyaw tshwj xeeb no tso cai rau cov kws kho mob ua cov kev xaiv txo qis yam tsis muaj kev xav sab nraud uas yuav tshwm sim nrog cov hauv paus muaj zog.
Nws tsim nyog sau cia tias thaum LAH yog qhov muaj txiaj ntsig zoo, nws qhov kev ua haujlwm siab kuj txhais tau tias nws yuav tsum tau ua tib zoo tuav. Cov kws kho mob yuav tsum siv cov dej tsis huv thiab ceev faj kom tsis txhob raug dej los yog huab cua thaum ua haujlwm nrog cov khoom sib xyaw no.
xaus
Hauv kev xaus, txawm hais tias cov khoom yuav tsis haum rau cov lus txhais ntawm lub hauv paus muaj zog, nws yeej pom cov khoom yooj yim nyob rau hauv qee yam mob. Nws cov reactivity nrog dej ua rau lub hauv paus muaj zog, thiab nws tag nrho cov cwj pwm ntawm cov tshuaj tiv thaiv feem ntau zoo li lub hauv paus muaj zog. Txawm li cas los xij, nws tau raug cais tawm raws li tus neeg sawv cev muaj zog nrog cov yam ntxwv tseem ceeb es tsis yog lub hauv paus muaj zog.
Txawm hais tias koj yog ib tus tub ntxhais kawm kawm txog cov tshuaj reagents los yog ib tug kws tshuaj raws caij nyoog ua hauj lwm ntawm complex syntheses, to taub tus cwj pwm nuanced ntawm cov tebchaw xws li cov khoom yog qhov tseem ceeb. Nws ua rau peb nco ntsoov tias hauv chemistry, xws li hauv ntau qhov kev tshawb fawb, kev faib tawm feem ntau tsis yog xim dub thiab dawb, tab sis qhov ntxoov grey uas yuav tsum tau ua tib zoo xav thiab cov ntsiab lus.
Raws li peb txuas ntxiv tshawb nrhiav thiab siv cov khoom tshwj xeeb ntawmLithium Aluminium Hydride, peb qhib qhov rooj rau qhov muaj peev xwm tshiab hauv cov organic synthesis, cov ntaub ntawv tshawb fawb, thiab lwm yam. Txoj kev taug kev ntawm kev tshawb pom hauv chemistry tseem tab tom ua tiav, thiab cov khoom sib txuas zoo li LAH ua lub luag haujlwm tseem ceeb hauv kev thawb cov ciam teb ntawm qhov ua tau hauv chav kuaj thiab hauv kev lag luam.
cov ntaub ntawv
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Finholt, AE, Bond Jr, AC, & Schlesinger, HI (1947). Lithium aluminium hydride, aluminium hydride thiab lithium gallium hydride, thiab qee qhov ntawm lawv cov kev siv hauv cov organic thiab inorganic chemistry. Phau ntawv Journal of the American Chemical Society, 69(5), 1199-1203.