DJA 3). Mecanisms simple editor Flashcards Preview

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Flashcards in DJA 3). Mecanisms simple editor Deck (17):
1

free radical

A chemical species with an unpaired electron - usually highly reactive`

2

how many stages to free radical substitution

3

3

what are the stages of free radical substitution (short)

initiationpropagationtermination

4

initiation

free radicals are producedCl2 -------> •Cl + •Cl 

5

Propagation

'Recycling the free radical'a). Cl• + CH3CH3 --------> CH3•CH2 + HCl (dot usually above C)b). CH3•CH2 + Cl2 -----> CH3CH2Cl + Cl • free radical used and then reformed                                              

6

Termination

Two free radicals collidingCH3•CH2 + Cl• ------->CH3CH2ClCl• + Cl• --------> NO JUST REFORMS WITH UV LIGHTCH3•CH2  + CH3•CH2 -------> CH3CH2CH2CH3

7

Further substitution

If Cl2 is in excess then the product will react with more and more Cl2.Then that new product wil react with more Cl2 and so on....

8

what is a nucleophile

a species that contains a lone pair of electrons 

9

3 examples of nucleophiles correctly written

 negative (xx) OH(xx) NH3negative (xx) CN

10

What happens during nucleophlic substitution

The nucleophile will swap places with another nucleophile on a molecule

11

Least reactive haloalkane

fluoro....

12

most freactive haloalkane

iodo.....

13

strongest haloalkane bond

fluoro....

14

weakest haloalkane bond

iodo...

15

explanation for strongest bond

shortest bond, electron pair in the bond is closest to the nucleus of F and there is little shielding therefore it is more strongly attracted

16

explanation for weakest bond

longest bond, electron pair in covalent bond is further away from the nucleus and there is more shielding so held less strongly

17

elimintaion what does negative (xx) OH act as

a base