Term
| Halogens add to alkenes to form ___________ ___________. |
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Definition
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Term
| A halogen molecule is ___________; a ___________ can react with a halogen, displacing a halide ion. |
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Definition
1) Electrophilic
2) Nucleophile |
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Term
An alkene halogen reaction generally features the ___________ electrons of the carbon-carbon double bond attacking a halogen molecule (say, bromine), expelling the ___________ ion.
A ___________ ion results, containing a three-membered ring with a ___________ charge on the ___________ atom.
Similar reactions with other halogens form other ___________ ions. |
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Definition
1) Pi
2) Bromine
3) Bromide
4) Positive
5) Bromine
6) Halonium |
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Term
Unlike a normal carbocation, all the atoms in a ___________ ion have filled octets; the three-membered ring has considerable ___________ ___________, however, combined with a ___________ charge on an electronegative halogen atom, making the ___________ ion strongly electrophilic.
Attack by a nucleophile, such as a ___________ ion, opens the halonium ion to give a stable product. |
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Definition
1) Halonium
2) Ring strain
3) Positive
4) Halonium
5) Halide |
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Term
*Mechanism 8-7: Addition of Halogens to Alkenes*
Step 1: Electrophilic attack forms a ___________ ion.
Step 2: The ___________ ion opens up the halonium ion. |
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Definition
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Term
___________ and ___________ commonly add to alkenes by the halonium ion mechanism.
___________ is used less frequently because diiodide products decompose easily. |
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Definition
1) Chlorine
2) Bromine
3) Iodination |
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Term
| In the halonium ion mechanism, solvents which are inert to the halogens, such as ___________ ___________, ___________, and ___________ ___________ should be used. |
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Definition
1) Methylene chloride
2) Chloroform
3) Carbon tetrachloride |
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Term
| The addition of bromine has been used a simple chemical test for the presence of ___________ double bonds. |
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Definition
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Term
| The addition of bromine to cyclopentene is a stereospecific ___________ ___________. |
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Definition
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Term
Anti stereochemistry results from the ___________ ion mechanism.
When a nucleophile attacks a ___________ ion, it must do so from the back side, in a manner similar to the SN2 reactions; this back-side attack assures ___________ stereochemistry of addition. |
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Definition
1) Bromonium
2) Halonium
3) Anti |
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