INDUCTIVE EFFECT

It involves (σ) sigma electrons.

The sigma electrons which form a covalent bond are seldom shared equally between the two atoms.

This is because different atoms have different electronegativity values. Electrons displaced towards the more electronegative atom, this introduces a certain degree of polarity in the bond. the more electronegative atom acquires a small negative charge, the less electronegative atom acquires a small positive charge.

+I Effect :-

Atoms or groups which lose electrons towards a carbon atom are said to have +I Effect.

EX:- F, Cl, Br, I, OH, NO₂C₆H₅

-I Effect :-

Atoms or groups which draws electrons from a carbon atom are said to have -I Effect.

EX:- (CH₃)₃ C- , (CH₃)₂CH- , CH₃CH₂- CH₃^-

MESOMERIC EFFECT:-

It involves π electrons of double and triple bonds. The mesomeric effect refers to the polarity produced in a molecule as a result of interaction between two π bonds or a one. and lone pair of electrons. the effect is transmitted along a chain in a similar way as are inductive effects.

The mesomeric effect is of great importance in conjugated compounds. in such systems, the π electrons get delocalized as a consequence of mesomeric effect, giving a number of resonance structures of the molecule. the mesomeric effect like the inductive effect may be positive or negative

+M Effect groups:-

Atoms which lose electrons towards carbon atom are said to have a +M Effect.

Ex:- Cl, Br, I, NH_2,OH,OCH₃

-M Effect groups:-

Atoms or groups which draw electrons away from a carbon atom are said to have -M Effect

Ex:-