Page 15 - Pharm.Org.Chem-I 02-06-05-101

Factors Affecting Electron
Availability at an Atom

• 1- Inductive effect
• 2- Resonance

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1- Inductive effect:

H2 H2 −
CH3 C C
Cl

+ + +

- I (out of Carbon) +I (to Carbon)
electron withdrawing gp electron donating gp

e.g. NO2,CN, SO3H,CHO, COR e.g.Alkyl groups
F,Cl,Br,I

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