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Why is the addition of Br2 to an alkene an electrophilic addition reaction? Watch

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    My text book says that when a Br2 molecule approaches the C=C in an alkene, a δ+ charge is induced on a nearer Br atom. Then this atom attracts the electrons in the C=C bond and forms a covalent bond.

    The Br-Br bond breaks heterolytically and the Br- ion forms a bond with the positively charged carbon.

    So why can't it be called a nucleophilic addition reaction instead of a electrophilic addition reaction ??
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    (Original post by batman000)
    My text book says that when a Br2 molecule approaches the C=C in an alkene, a δ+ charge is induced on a nearer Br atom. Then this atom attracts the electrons in the C=C bond and forms a covalent bond.

    The Br-Br bond breaks heterolytically and the Br- ion forms a bond with the positively charged carbon.

    So why can't it be called a nucleophilic addition reaction instead of a electrophilic addition reaction ??
    The Br delta+ is behaving as electrphile and reacts with the electron rich double bond. This results in an intermediate carbocation which atracts the Br-

    I suppose you could consider that last step to be a "nucleophilic addition". That woulld however miss the point of how the reaction initiates.

    Any addition "across" an insaturated bond will be electrophilic.
    An electrphile is required to initiate the "opening up" of the double bond.
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    (Original post by TutorsChemistry)
    The Br delta+ is behaving as electrphile and reacts with the electron rich double bond. This results in an intermediate carbocation which atracts the Br-

    I suppose you could consider that last step to be a "nucleophilic addition". That woulld however miss the point of how the reaction initiates.
    Thanks. That does make sense.
 
 
 
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