Why the hydroxyl group in phenols acts as a electron donating group?

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Solution

actually OH group is electron releasing as well as electron withdrawing group ...

-I effect (inductive effect) => in accordance with this effect OH group will show -I (electron withdrawing) effect due to presense of an electronegative Oxygen atom ...

+R effect (resonance effect) => in accordance with this effect OH group will show is +R(electron releasing ) effect due to presence of lone pair of electrons on oxygen ...

when ever their is comparision in bw resonance & inductive or hyperconjugation then more priority is given to

resonance effect ....

example -> CH₃CH₂OH - -I effect , no resonance - OH group is electron withdrawing

CH₂=CH-OH - -I effect , +R effect - OH group electron releasing (possiblity of resonance)

phenol - -I effect , +R effect - OH group is electron releasing (possiblity of resonance)

this is not always true that if OH is attached to aliphatic molecules then it is EWG , if there is

possiblity of resonance then it will become EDG ...

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Similar questions

Among follwing Electron donating groups are:

a) $- C l$

b) $- C O -$

c) $- N O_{2}$

d) $- O H$

e) $- N H_{2}$

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