Thaum HBr ntxiv rau alkene nyob rau hauv muaj h2o2?
Thaum HBr ntxiv rau alkene nyob rau hauv muaj h2o2?

Video: Thaum HBr ntxiv rau alkene nyob rau hauv muaj h2o2?

Video: Thaum HBr ntxiv rau alkene nyob rau hauv muaj h2o2?
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Qhov no yog hu ua Markovnikov's Rule. Vim lub HBr ntxiv rau "kev tsis ncaj ncees ib puag ncig" hauv cov muaj nyob ntawm cov organic peroxides, qhov no feem ntau hu ua cov nyhuv peroxide lossis anti-Markovnikov ntxiv . Thaum tsis muaj peroxides, hydrogen bromide ntxiv rau propene ntawm electrophilic ntxiv tshuab.

Ntawm no, thaum HBr ntxiv rau alkene Dab tsi yog lub luag haujlwm ntawm HBR hauv cov tshuaj tiv thaiv?

HBr Ntxiv rau Alkene . HBr ntxiv rau alkenes los tsim alkyl halides. Ib txoj hauv kev zoo los xav txog cov tshuaj tiv thaiv yog tias tus pi daim ntawv cog lus ntawm lub alkene ua raws li qhov tsis muaj zog nucleophile thiab reacts nrog electrophilic proton ntawm HBr . Xwb, koj tuaj yeem saib thawj kauj ruam ntawm cov tshuaj tiv thaiv raws li protonation ntawm pi daim ntawv cog lus.

Ib tug kuj yuav nug, yuav ua li cas tshwm sim thaum propene raug kho nrog HBr nyob rau hauv muaj peroxide? Yog tsis muaj a peroxide , HBr ntxiv rau propene ntawm ib qho ionic mechanism (nrog rau carbocation nruab nrab) muab 2-bromopropane. Hauv muaj nyob ntawm a peroxide xws li HOOH, HBr ntxiv rau propene Nyob rau hauv lub anti-Markovnikov kev nkag siab thiab ntawm ib tug radical mechanism, muab 1-bromopropane.

Vim li cas cov nyhuv peroxide tsuas pom nrog HBr?

Nyob rau hauv lub xub ntiag ntawm peroxide thiab lub teeb, ntxiv ntawm HBr rau unsymmetrical alkenes tshwm sim contrary Markovnikov txoj cai. Tab sis HCl thiab HI tsis qhia cov nyhuv peroxide . Radical chain reactions muaj kev vam meej thaum kev nthuav tawm cov kauj ruam yog exothermic. Nrog HI, thawj kauj ruam nthuav tawm yog endothermic, vim H-I daim ntawv cog lus tsis muaj zog.

Yuav ua li cas thaum HBr ntxiv rau propene?

Nrog HBr , propene nkag siab thiab muab 2-bromopropane ua cov khoom loj thiab 1-bromopropane ua cov khoom me. HBr molecule yog ntxiv hla ob daim ntawv cog lus ntawm propene . Marconikov txoj cai yog siv los nrhiav qhov chaw (uas carbon atom hauv ob daim ntawv cog lus) ntawm hydrogen thiab bromine atoms yog ntxiv.

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