What are electron deficient compounds? Is BCl3 electron deficient species?
Species in which the central atom either does not have eight electrons in the valence shell or those which have 8 electrons in the valence shell but can expand their covalency beyond 4 due to the presence of d-orbitals are called electron deficient molecules.
BCl3 is an electron deficient compound because the central boron atom has only six electrons. As a result, it accepts a pair of electrons from NH3 to form an adduct.
