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Is inductive effect stronger than resonance?

When the substituents like -OH have an unshared pair of electrons, the resonance effect is stronger than the inductive effect which make these substituents stronger activators, since this resonance effect direct the electron toward the ring.

Which is the strongest electron withdrawing group?

An electron withdrawing group (EWG) is a group that reduces electron density in a molecule through the carbon atom it is bonded to….The strongest EWGs are groups with pi bonds to electronegative atoms:

  • Nitro groups (-NO2)
  • Aldehydes (-CHO)
  • Ketones (-C=OR)
  • Cyano groups (-CN)
  • Carboxylic acid (-COOH)
  • Esters (-COOR)

What is the difference between electron donating and electron withdrawing?

The key difference between EDG and EWG is that the EDG (stands for Electron Donating Groups) can increase the electron density of a conjugated pi system whereas the EWG (stands for Electron Withdrawing Groups) decreases the electron density of a conjugated pi system.

Why Mesomeric effect is stronger than inductive effect?

The ionization potential of pi-electrons is smaller and chemical bond is more polarizable. Therefore, the dipole moment associated with the mesomeric effect can prevail over the dipole moment associated with the inductive effect.

Is Mesomeric effect permanent?

Out of these four effects, the mesomeric effect is the most widely applicable and more significant effect. It is also a permanent effect.

What is +I effect and effect?

In chemistry, the inductive effect is an effect regarding the transmission of unequal sharing of the bonding electron through a chain of atoms in a molecule, leading to a permanent dipole in a bond. In short, alkyl groups tend to donate electrons, leading to the +I effect.

What is plus R effect and minus I Effect?

The main difference between resonance and the mesomeric effect is that the resonance effect describes how a molecule’s lone electron pair and bond electron pair determine its chemical structure, whereas the mesomeric effect describes how a molecule’s chemical structure is stabilized by using a functional group.

Which has more +R effect OH or OCH3?

OH (hydroxy) has a better +R effect than OCH3 because The -CH3 group in -OCH3 causes steric repulsions with lone pairs, increasing bond angles. Due to which it make -O- atom of -OCH3 more electro-negative and thus affecting donor tendency.

Why is oh more activating than OCH3?

OH group is more activating than OR. Because OH group has more electron donating group . We can better understand it in he case of Phenol. Phenols have highly electron donating group i.e. hydroxyl group due to which the benzene ring has high electron density at ortho and para postions .

Is nitro electron donating or withdrawing?

Numerous studies on nitro group properties are associated with its high electron-withdrawing ability, by means of both resonance and inductive effect.

Which is more electron withdrawing OCH3 or Oh?

OCH3 group is more electron withdrawing (i.e, shows more -I effect) than the OH group. Explanation: The reason is that, there are two lone pairs of oxygen. However, in case of OH, the H atom is comparatively much much smaller than O, so here no Steric repulsion takes place.

Is Oh electron donating or withdrawing?

For example, an oxygen atom in a hydroxy group (OH) is electron withdrawing by induction, but electron donating by resonance when placed in a position on the structure where resonance is possible This will be explained more fully below.


Yes, OCH3 which belongs to the is the electron-withdrawing group (methoxy group). Here, the oxygen (in OCH3) is more electronegative than carbon due to which it will show -I effect which is electron-withdrawing.

Is Cho an electron withdrawing group?

Note: The presence of (-CHO) group or aldehydic group increases the acidic character of the compound because it is an electron withdrawing group.

Is F or Cl A better electron withdrawing group?

Hence, halogens (fluorine, chlorine, etc) are electron withdrawing groups. C-Cl bond is more stronger in comparison to Cl-Cl bond because as we know more the electronegativity difference between the two atom stronger the bond is ,so there is more electronegativity difference in between C-Cl.

Is NO2 EWG or EDG?

NO2 is an amazing electron withdrawing group, along with carbonyls. Electron withdrawing groups make it more difficult to introduce new groups onto the ring. They are also meta directing and deactivate a benzene ring.

Is Oxygen an EWG or EDG?

The oxygen atom does indeed exert an electron-withdrawing inductive effect, but the lone pairs on the oxygen cause the exact opposite effect – the methoxy group is an electron-donating group by resonance.


Electron withdrawing groups have an atom with a slight positive or full positive charge directly attached to a benzene ring. Examples of electron withdrawing groups: -CF3, -COOH, -CN. Electron withdrawing groups only have one major product, the second substituent adds in the meta position.

Is benzene EWG or EDG?

Benzene is a electron withdrawing by inductive effect and electron donating by resonance (depends on the substituents attached to the benzene ring).

Is NMe2 electron withdrawing?

The -NMe2 substituents withdraws electron density via the inductive effect, but, the inductive effect is overwhelmed by the resonance donating effect, -NMe2 is overall electron donating.

Is oh a EDG or EWG?

Oxygen is much more electronegative than carbon so it can withdraw electron density by the inductive effect. However, it is very important to note that OH is NOT an electron withdrawing group. It is an electron DONATING group.

Why is COOH electron withdrawing?

Carboxylic acid is a much better acid than the equivalent alcohol, so it results in a more stable ion as it lacks its proton. Some atoms or groups are electron-withdrawing when bound to a carbon, as contrasted with a hydrogen atom in the same position.

Is och3 EWG or EDG?

Is CL electron donating or withdrawing?

Although chlorine is an electron withdrawing group, yet it is ortho-para directing in electrophilic aromatic substitution reaction.

Is BR Ortho para or meta?

Some common ortho para directing groups are –Cl, -Br, -I, -OH, -NH2, -CH3, -C2H5. The group which directs the second incoming group to the meta position, is called a meta-director. For example, alkylation of nitro benzene gives m-alkylnitro benzene as major product.