Delocalised π system and electron density
What Delocalised π system and electron density means in Chemistry A-Level, as defined for OCR.
Definitions of Delocalised π system and electron density
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Reference: OCR
Donating the oxygen lone pair into the delocalised π-system increases the electron density, especially at the 2- and 4-positions, and a higher electron density attracts electrophiles more strongly.
The oxygen's lone pairs overlap with the ring's delocalised π system, so the ring becomes more electron-rich than benzene and attracts electrophiles more strongly.
Topics that use Delocalised π system and electron density
- Aromatic compounds (OCR A-Level)
Related terms
- Activating and 2,4-directing effect of the –OH group
- Bond lengths in benzene
- Carbon–carbon bond formation in synthesis
- Comparison with carboxylic acids and the carbonate test
- Delocalised π system in benzene
- Directing effects
- Directing effects of OH, NH₂ and NO₂
- Directing effects of the –OH group
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