What are electron deficient compounds ? Is `BCl_3` an electron deficient species ? Explain.

Explanation

These are the compounds in which the available no.of valence electrons is lessthan the number required for normal covalent bond formation (or) for writting the Lewis structure of the molecule.
`to` These compounds are electron pair acceptors and acts as Lewis acids. `to` `BCl_3` is an electron deficient compound.
In `BCl_3` .B. contains only six electrons instead of eight electrons.
`to` `BCl_3` has the tendency to accept an electron pair and acts as Lewis acid.
Eg : Formation of `BCl_3 . NH_3` :-
`BCl_3` accepts an electron pair from `NH_3` and forms the compound `BCl_2.NH_3` (Tetrahedral)