chemistry facts
CONCEPTS IN ORGANIC CHEMISTRY
• Inductive Effect : Inductive effect is defined as permanent displacement of shared electron pair in a carbon chain towards more electronegative atom or group.
Types of Inductive effect :
1.Negative Inductive Effect : (—I effect,
Electron withdrawing effect) when an electronegative atom or group
(more electro negative than hydrogen)is attached to the terminal of the carbon chain in a compound, the electrons are displaced in the direction of the attached atom or group.
-NO2 > -CN > -COOH > F > Cl > Br > I > OH > C6H5
>H
2. Positive Inductive effect : (+I effect, Electron releasing effect)
When an electro positive atom or group
(more electro positive than hydrogen)is attached to the terminal of the carbon chain in a compound, the electrons are displaced away from the attached atom or group.
(CH3)3C- > (CH3)2CH- > -C2H5 > - CH3.
Applications of Inductive effect:
Inductive effect is useful in explaining the strength of some organic acids and bases.
a) Effect of substituent on the acid strength of aliphatic acids. HCOOH > CH3COOH > (CH3)2CHCOOH
Reason : Acidic strength decreases as +I effect of the alkyl group increases.
b) O2NCH2COOH > FCH2COOH >CICH2COOH >
BrCH2COOH> ICH2COOH > CH3COOH
Reason : Acidic strength decreases as -I effect of the group or halogen decreases.
Applications of Inductive effect:
c) Cl3CCOOH > Cl2CHCOOH> ClCH2COOH >
CH3COOH
Reason : Acidic strength decreases as the number of halogen atoms decreases.
d) CH3CHClCOOH > CH2ClCH2COOH
Reason : Acidic strength decreases as the distance of the halogen from carboxylic group increases.
e)
i.e., Benzoic acid is stronger than acetic acid.
Reason : due to –I effect of phenyl group.
Relative basic strength of amines
1. All aliphatic amines are more basic than ammonia.
e.g. Methyl amine is more basic than ammonia.
Reason : Due to +I effect of methyl group.
2. Aniline is weaker base than Ammonia.
Reason : Due to
• Inductive Effect : Inductive effect is defined as permanent displacement of shared electron pair in a carbon chain towards more electronegative atom or group.
Types of Inductive effect :
1.Negative Inductive Effect : (—I effect,
Electron withdrawing effect) when an electronegative atom or group
(more electro negative than hydrogen)is attached to the terminal of the carbon chain in a compound, the electrons are displaced in the direction of the attached atom or group.
-NO2 > -CN > -COOH > F > Cl > Br > I > OH > C6H5
>H
2. Positive Inductive effect : (+I effect, Electron releasing effect)
When an electro positive atom or group
(more electro positive than hydrogen)is attached to the terminal of the carbon chain in a compound, the electrons are displaced away from the attached atom or group.
(CH3)3C- > (CH3)2CH- > -C2H5 > - CH3.
Applications of Inductive effect:
Inductive effect is useful in explaining the strength of some organic acids and bases.
a) Effect of substituent on the acid strength of aliphatic acids. HCOOH > CH3COOH > (CH3)2CHCOOH
Reason : Acidic strength decreases as +I effect of the alkyl group increases.
b) O2NCH2COOH > FCH2COOH >CICH2COOH >
BrCH2COOH> ICH2COOH > CH3COOH
Reason : Acidic strength decreases as -I effect of the group or halogen decreases.
Applications of Inductive effect:
c) Cl3CCOOH > Cl2CHCOOH> ClCH2COOH >
CH3COOH
Reason : Acidic strength decreases as the number of halogen atoms decreases.
d) CH3CHClCOOH > CH2ClCH2COOH
Reason : Acidic strength decreases as the distance of the halogen from carboxylic group increases.
e)
i.e., Benzoic acid is stronger than acetic acid.
Reason : due to –I effect of phenyl group.
Relative basic strength of amines
1. All aliphatic amines are more basic than ammonia.
e.g. Methyl amine is more basic than ammonia.
Reason : Due to +I effect of methyl group.
2. Aniline is weaker base than Ammonia.
Reason : Due to