The p pi- p piback bonding occurs in the halides of boron and not in those of aluminium. Explain.

The p pi- p piback bonding occurs in the halides of boron and not in t

1.	The p pi- p piback bonding occurs in the halides of boron and not in those of aluminium. Explain.
Answer» <P> Solution :The tendency to show `p pi -p pi` BACK bonding depends upon the size of central ATOM. This tendency decreases as the size of the central atom in a group increases. SINCE aluminium has LARGER size than boron, the back bonding is not possible.