The electrons of the covalent bond formed between two different atoms migrate to a more negative electrical atom. This type of displacement of electrons in molecules is called the inductive effect. This is a permanent effect.
The electrons of the covalent bond formed between similar atoms lie exactly in the middle of both atoms and the separation of charge in this type of molecule does not mean polarization.
For example: In H2, CH3-CH3 and Cl2 molecules do not have a displacement of H-H, C-C, and Cl-Cl bond electrons. And the induction effect is not present in these molecules. In contrast, the electrons of the covalent bond formed between different atoms migrate to the more negative electric atom, and such molecules have polarisation and inductive effect present.
In CH3Cl, two electrons of the C – Cl bond are partially displaced towards the Cl atom. This causes a partial positive charge on the C atom and partial negative charge on the Cl atom.
Major symptoms of inductive effects
Inductive effects results in the only partial displacement of the electrons and electrons do not completely transfer from the octave of one atom to the octave of another atom. Partial displacement results in partial charge generation. Display partial positive charge from + σ and partial negative charge with – σ.
This effect is transmitted from one end to another in a series of carbon atoms. As the atoms that produce this effect keep away from it, the effect keeps on decreasing.
The polarity of the double and tri bond is less than that of the single bond. If two and three bonds are present in a series of carbon atoms, then this effect is transmitted to a greater extent in the chain.
The amount of partial positive charge present on C4 in the first compound above will be less than the amount of partial positive charge present on C4 in the second compound.
Let us denote the inductive effect from I. Groups in which the effect of this effect is higher in attractive to electrons than hydrogen. They are called the -I group. Groups that have lower attract to electrons than hydrogen. They are called + I groups.
Uses of Inductive Effect
The concept of inductive effect helps in clarifying the mechanism of many reactions and many other facts. With its help, the acid strength of acids and the power of the base can be compared.
What is I-effect?
Shifting of electrons in covalent bond from low electronegative atom to high electronegative atom.
Always sigma (σ) electrons are displaced (only occur in single bond)