Term
| electron-donating groups .......... the ring and direct to ortho/...... |
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Definition
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Term
which of the following is not an ortho/para director?
-NH2 amino
-OH hydroxy
-NO2 nitro
-X halogen |
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Definition
-NO2 is not an ortho/para director. it is a meta director.
the following are ortho/para directors (electron-donating groups)
NH2, -OH, -OR, -R, -X
amino, hydroxy, alkoxy, alkyl and halogen |
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Term
| electron-withrawing groups .......... the ring and direct to ........... |
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Definition
deactivate
meta
NO2, -SO3H, -CN, -COOR, -COR/-CHO are all electron-withdrawing meta directors.
nitro, sulphonic acid, nitrile, ester or acid, acyl or formyl |
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Term
| if an alkoxy group was to meta direct, the arenium ion would be a resonance hybrid of how many lewis structures? |
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Definition
3.
therefore the alkoxy group directs ortho/para because the intermediate has a more stable 4 lewis structured resonance hybrid which results in more effective charge delocalisation than those for meta substitution |
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Term
ortho/para directors:
any substituent with a ...... ...... on the atom directly bound to the ring behaves like the -OCH3 group and stabilises the arenium ion intermediates for otho/para substitution |
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Definition
lone pair.
NH2, -OH, -OR, -R, -X are all ortho/para directors |
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Term
| why is the resonance effect more dominant than the inductive effect? |
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Definition
| it gives the intermediates for ortho/para substitution a 4th resonance form. |
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Term
true or false
the intermediates for ortho/para substitution are more stable than the intermediate for meta substitution |
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Definition
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Term
| in which substituiton of nitrobenzene does the nitro group prevent charge delocalisation in the arenium ion |
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Definition
| ortho/para substituiton. charge distribution on the arenium ion in ortho/para substitutions of nitrobenzene is strongly disfavoured |
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