Qhov sib txawv tseem ceeb ntawm alpha thiab beta tshem tawm cov tshuaj tiv thaiv yog tias nyob rau hauv alpha tshem tawm cov tshuaj tiv thaiv, ob pawg tawm tawm ntawm tib lub atom whereas, nyob rau hauv beta tshem tawm cov tshuaj tiv thaiv, ob pawg tawm tawm ntawm ob lub atoms uas nyob ib sab ntawm tib lub molecule.
Kev tshem tawm cov tshuaj tiv thaiv yog ib hom tshuaj tiv thaiv organic uas muaj ob qhov hloov pauv tau raug tshem tawm ntawm ib lub molecule. Qhov kev tshem tawm no yog ua nyob rau hauv ib kauj ruam cov tshuaj tiv thaiv los yog hauv ob kauj ruam mechanism. Cov txheej txheem ib kauj ruam yog suav tias yog E2 cov tshuaj tiv thaiv thaum ob-kauj ruam mechanism yog denoted li E1 cov tshuaj tiv thaiv. Hauv cov ntsiab lus no, tus lej uas tuaj nrog tsab ntawv E yog hais txog kinetics ntawm cov tshuaj tiv thaiv, e.g. Cov tshuaj tiv thaiv E2 yog cov tshuaj tiv thaiv bimolecular (kev txiav txim thib ob) thaum E1 cov tshuaj tiv thaiv tsis muaj tshuaj tiv thaiv (thawj thawj). Ntxiv rau qhov ntawd, muaj ob hom kev tshem tawm cov tshuaj tiv thaiv npe hu ua alpha tshem tawm thiab beta tshem tawm, tom kawg yog hom kev tshem tawm ntau tshaj plaws.
Alpha Elimination Reaction yog dab tsi?
Alpha tshem tawm cov tshuaj tiv thaiv yog ib hom tshuaj tiv thaiv organic uas ob pawg tawm tawm ntawm tib lub atom hauv cov molecule. Nws yog hom thib ob feem ntau ntawm kev tshem tawm cov tshuaj tiv thaiv thiab yog qhia los ntawm α-kev tshem tawm. Thaum muaj cov pa roj carbon monoxide nyob rau hauv cov molecule uas dhau qhov kev tshem tawm cov tshuaj tiv thaiv, qhov kawg tshwm sim yog tsim cov carbene, uas suav nrog cov carbenes ruaj khov xws li carbon monoxide thiab isocyanides. Piv txwv li, alpha tshem tawm ntawm chloroform molecule, CHCl3, nyob rau hauv lub xub ntiag ntawm ib tug muaj zog puag muab dichlorocarbene nrog rau HCl raws li lub tshem tawm compound los yog cov pab pawg neeg tawm. Hauv cov tshuaj tiv thaiv no, muaj ib lub chaw carbon uas muaj peb chlorine atoms thiab hydrogen atom txuas rau nws. Kev tshem tawm tshwm sim ntawm no ib qho carbon atom; tawm hauv pawg yog hydrogen atom thiab ib chlorine atom.
Daim duab 01: Piv txwv ntawm Alpha thiab Beta tshem tawm cov kev tshwm sim
Ib yam li ntawd, formic acid kuj tuaj yeem raug tshem tawm alpha. Cov khoom ruaj khov ntawm qhov kev tshem tawm cov tshuaj tiv thaiv no suav nrog dej thiab carbon monoxide nyob rau hauv lub xub ntiag ntawm acidic mob. Ntxiv mus, kev tshem tawm alpha tuaj yeem tshwm sim hauv lub chaw hlau, uas tuaj yeem ua rau txo qis ntawm cov hlau oxidation xeev thiab kev sib koom tes ntawm 2 units. Li no, hom tshuaj tiv thaiv no yog hu ua kev tshem tawm kom txo qis.
Yuav ua li cas tshem tawm Beta Reaction?
Beta tshem tawm cov tshuaj tiv thaiv yog ib hom tshuaj lom neeg uas muaj ob pawg tawm ntawm ob lub atoms uas nyob ib sab. Hauv lwm lo lus, beta tshem tawm yog qhov poob ntawm electrofuge thiab nucleofuge ntawm vicinal carbons. Qhov no yog hom kev tshem tawm ntau tshaj plaws hauv cov organic chemistry.
Raws li cov khoom kawg ntawm cov tshuaj tiv thaiv no, kev tshem tawm beta tsim cov khoom uas muaj C=C thiab C=X daim ntawv cog lus. Thaum xav txog qhov ruaj khov ntawm cov khoom kawg thiab kev sib haum xeeb orbital, cov tshuaj tiv thaiv beta tshem tawm yog qhov zoo dua li lwm hom kev tshem tawm cov tshuaj tiv thaiv. Txawm li cas los xij, muaj lwm yam xws li alpha tshem tawm thiab gamma tshem tawm rau cov tshuab uas tsis nyiam alpha tshem tawm.
Qhov txawv ntawm Alpha thiab Beta tshem tawm cov tshuaj tiv thaiv yog dab tsi?
Alpha thiab beta tshem tawm yog ob hom tshuaj lom neeg cov tshuaj tiv thaiv. Qhov sib txawv tseem ceeb ntawm alpha thiab beta tshem tawm cov tshuaj tiv thaiv yog tias nyob rau hauv alpha tshem tawm cov tshuaj tiv thaiv, ob pawg tawm tawm ntawm tib lub atom whereas, nyob rau hauv beta tshem tawm cov tshuaj tiv thaiv, ob pawg tawm tawm ntawm ob lub atoms uas nyob ib sab ntawm tib molecule.
Hauv qab infographic tabulates qhov sib txawv ntawm alpha thiab beta tshem tawm cov tshuaj tiv thaiv kom ntxaws ntxiv.
Summary – Alpha vs Beta Elimination Reaction
Alpha thiab beta tshem tawm yog ob hom tshuaj lom neeg cov tshuaj tiv thaiv. Qhov sib txawv tseem ceeb ntawm alpha thiab beta tshem tawm cov tshuaj tiv thaiv yog tias nyob rau hauv alpha tshem tawm cov tshuaj tiv thaiv, ob pawg tawm tawm ntawm tib lub atom whereas, nyob rau hauv beta tshem tawm cov tshuaj tiv thaiv, ob pawg tawm tawm ntawm ob lub atoms uas nyob ib sab ntawm tib molecule.
