Electrophilic and repellent groups are common

Common electron-withdrawing groups.

Electron siphoning induction effect.

Denoted by -i): no >cn>f>cl>br>i>c3c>och >oh>c h >c=c>h.

Common electron-donor groups (electron-donor induced effects are denoted by +i) :(ch) c>(ch) c>ch ch >ch >h.

In terms of induction effect, electronegativity.

Anything greater than hydrogen is electrically absorbed, and anything less electronegativity than hydrogen is powered, but the alkyl groups are all powered.

from the conjugation effect.

Above, there are lone pairs of electrons.

All belong to power supply, and those with double or triple bonds belong to power absorption, but carbon carbon double bonds.

and phenyl groups, which are powered.

Common electrophilic groups of electrophilic groups (electron withdrawing induction effects are denoted by -i) NO2 > CN > F > Cl > BR > I > C TriC > Oh There are also carboxyl groups, cyano groups, ester aldehyde groups, electron repulsion groups: (C(CH3)3> (CH3)2C> CH3CH2 > CH3 > H and amino groups,

I would like to know how to determine the electron absorption and donor effects of some complex groups (i.e., the conjugation effect and the induction effect, the spatial effect of the occlusion group, the spatial effect of the occlusion group, and the discussion of the electrons of the aromatic ring electrophilic substitution reactive alkyl group.

<> electron-withdrawing groups:

1. Strong electron-withdrawing groups: tertiary amine cation, nitro, trihalomethyl;

2. Medium electron withdrawing group: cyano group, sulfonic acid group;

3. Weak electron-withdrawing groups: formyl group, acyl group, carboxyl group.

Give electron groups:

1. Super electron-donor group: oxygen anion;

2. Strong donor groups: dialkyl amino group, alkyl amino group, amino group, hydroxyl group, alkoxy group;

3. Medium electron-donor group: amide group, acyloxy group;

4. Weak electron-donor groups: alkyl group, carboxymethyl group, phenyl group.

The results of the ranking of the strength of the common electron withdrawing and donor groups are as follows:

1. Common electron withdrawing groups (electron withdrawing induced effects are denoted by -i):

NO2 > CN > F > Cl > BR > I > C Triple C > OCH3 > OH > C6H5 > C=C > H ;

2. Common electron-donor groups (electron-giving induced effects are denoted by +i):

ch3)3c > ch3)2c > ch3ch2 > ch3 > h.

The specific explanation is as follows:

The electron withdrawing or electron donating effect is specific to the atom or molecule to which it is attached, for example, if a nitro group is attached to a benzene ring, then the p-benzene ring is electron withdrawing.

Because the connection between nitro and oxygen is that a nitrogen atom and two oxygen atoms are connected by double bonds respectively, and the electronegativity of oxygen is greater than that of nitrogen, therefore, the electron cloud of the two double bonds is biased towards oxygen, so the electron cloud of the whole group is biased towards oxygen under the pull of the two oxygen. So, this group p-benzene ring is electron-withdrawing.

Comparing another group CN, nitrogen is more electronegative than carbon, so the electron cloud is biased towards nitrogen. In the same way, this group is also electron-withdrawing. For the latter och3 and oh, it can be explained that the lone pair of electrons on oxygen has both the induction effect of electron withdrawing and the conjugation effect of electron, and the sum of the two effects weakens its electron withdrawing effect mode.

Types of electronic effects of the two groups attacking the shouting:

In most reactions, the electron density of some part of the molecule decreases or rises because the substituents (compared to hydrogen atoms) tend to donate or withdraw electrons, causing the reactive molecule to have a positive (or partially positive) or negative (or partially negative) effect at some stage.

The electron effect is a theory that is proposed to explain chemical phenomena based on a large number of experimental facts. There are two types of electronic effects: inductive effect and conjugative effect.

The induction effect is a short-range electronic effect based on a localized bond. The conjugation effect is a long-range electronic effect based on a delocalized bond, and in organic compounds, the two effects often exist at the same time.

1. Electron withdrawing group.

1. Strong electron-withdrawing group.

Tertiary amine cation (-N+R3), nitro (-NO2), trihalomethyl (-CX3) x=f, cl

2. Medium-withdrawing electron groups.

Cyano (-CN), sulfonic acid (-SO3H).

3. Weak electron-withdrawing groups.

Formyl (-cho), acyl (-cor), carboxyl (-cooh).

2. Push electron groups.

1. Super strong group.

Oxygen anion (-o-).

2. Strong electron donor group.

Diaalkyl amino (-NR2), alkyl amino (-NHR), amino (-NH2), hydroxyl (-OH), alkoxy (-or).

3. Medium groups.

Amide group (-NHCOR), acyloxy group (-OCOR).

Summary. Hello dear! Glad to answer for you, the definition of electron-pulling group and electron-donor group is a common electron group (electron-withdrawing induced effect is denoted by -i) NO2 > CN > F > Cl > Br > I > C TriC > OCH3 > OH > C6H5 > C=C > H Common electron-donor groups (electron-donor induced effects are denoted by +i) (CH3) 3C > CH3)2C > CH3CH2 > CH3 > H.

Is it there? Teacher.

There is no specific pull of electrons and the definition given to the electron group.

Hello dear! Glad to answer for you, the definition of electron-pulling group and electron-donor group is a common electron group (electron-withdrawing induced effect is accompanied by -i epidermis) NO2 > CN > F > Cl > br > I > C TriC > och3 > oh > C6H5 > C=C > H common bright hold donor group (electron-induced lead effect is represented by +i) (CH3) 3C > CH3)2C > CH3CH2 > CH3 > h. <>

What kind of textbook does this appear in?

I was able to see it myself, mainly I couldn't find it.

Pro,f,-oh--nh is obtained after hf,ho,nh loses protons, and the corresponding ions are negative valent and therefore electron-donor groups. 2.The electron-donor group is disturbed when substituting the hydrogen on the benzene ring, and the group with increased relative density of the electron cloud on the benzene ring is a common electron-withdrawing group (the electron-withdrawing induced effect is denoted by -i) NO2 > CN > F > Cl > Br > I > C Tric > OCH3 > OH > C6H5 > C=C >.

1. Electron withdrawing group.

1. Strong electron-withdrawing group.

Tertiary amine cation (-N+R3), nitro (-NO2), trihalomethyl (-CX3) x=f, cl

2. Medium-withdrawing electron groups.

Cyano (-CN), sulfonic acid (-SO3H).

3. Weak electron-withdrawing groups.

Formyl (-cho), acyl (-cor), carboxyl (-cooh).

2. Push electron groups.

1. Super strong group.

Oxygen anion (-o-).

2. Strong electron donor group.

Diaalkyl amino (-NR2), alkyl amino (-NHR), amino (-NH2), hydroxyl (-OH), alkoxy (-or).

3. Medium groups.

Amide group (-NHCOR), acyloxy group (-OCOR).

<> electron-withdrawing groups:

1. Strong electron-withdrawing group.

Tertiary amine cation (-N+R3), nitro (-NO2), trihalomethyl (-CX3) x=f, cl

2. Medium-withdrawing electron groups.

Cyano (-CN), sulfonic acid (-SO3H).

3. Weak electron-withdrawing groups.

The formyl group (-cho) is clear, the acyl group (-cor), and the carboxyl group (-COOH).

Push electron groups.

1. Super strong group.

Oxygen anion (-o-).

2. Strong electron donor group.

Diaalkyl amino (-NR2), acetaminyl amino (-NHR), amino (-NH2), hydroxyl (-OH), alkoxy (-or).

3. Medium groups.

Amide group (-NHCOR), acyloxy (-OCOR).

Nitro and cyano.

1. Nitro. Nitro is a concept in chemistry that refers to the group left after the removal of one hydroxyl group from a nitric acid molecule. Compounds where the nitro group is attached to other groups, mainly hydrocarbon groups, are called nitro compounds.

2. Cyanide. The carbon and nitrogen atoms in the cyano group (CN) are connected by triple bonds. This triple bond gives the cyano group a fairly high degree of stability, allowing it to exist as a single unit in the usual chemical reactions. <>

Electron donor group: A group that exhibits a negative electric field externally.

Electron-withdrawing group: A group that exhibits a positive electric field externally.

2.The electric field exhibited by the group is identified by the reduction method according to the electronegativity.

Reduction method: add a hydrogen atom (-H) or hydroxyl group (-OH) to the group to form a central element valency is a commonly used molecule, so that the molecule is neutral, the hydrogen atom is positively charged, the hydroxyl group is negatively charged, and the electrical properties of the remaining groups can be judged.

For example, methyl group (CH3) is reduced to methane by adding a hydrogenous brigade balance (-H) to it, because we know that methane is a molecule that is point neutral, and the electronegativity of hydrogen atoms is very low, and it usually shows a positive electric field when combined with other groups, so the methyl group should show a negative electric field, and according to the above definition, it can be known that methyl group is the power supply group.

Then change the bucket for example: nitro group (NO2), add a hydroxyl group (-OH) to it by the reduction method to make it constitute a nitric acid molecule (HNO3), because the hydroxyl group is negatively charged, so the nitro group is positively charged, and according to the above definition, it can be known that the nitro group is an electron-withdrawing group.

This is summarized by others, this analysis method is suitable for the analysis of universal groups (of course, including benzene ring), and can also be used to help understand the induction effect, conjugation effect, activation and passivation and other effects, I hope these will be helpful to everyone, but it is better for you to remember those are power supply groups, and those are power absorbing groups. ,9,