Question

What does n stand for in huckel's rule?

Answer 1

Isn't \(n\) integer there ??

Answer 2

yes it is but physical meaing?

Answer 3

meaning*

Answer 4

There are four main criteria to decide the Aromaticity of an organic compound

a) The compound should have a cyclic nature
b) The compound should have a planar structure to ensure a good overlap of p-orbitals
c) The compound should be conjugated i.e. each atom of the ring should have a p-orbital for continuous delocalisation of the electrons within the pi-cloud of the ring
d) The compound should have (4n+2)pi electrons [Huckel Rule] {where n = 0,1...}

The value of n can be ANY Integer as long as you are able to equate the number of electrons in the pi orbital to the Huckel's Rule.

For Eg:- In Benzene, each of the Carbon Atom is sp2 hybridised.

So, each of the atom has 1 electron in it's free p-orbital, making it (6pi) electrons in all.

By using an appropriate value of 'n' , ( In this Case, n = 1), we can equate
4n + 2 = 6

Thus, we can such create an equation for each atom, and if we get an integral value for n, then the compund follows Huckel's Rule.