Question

What do you understand by outer orbital complex?

What are high-spin complexes?

Answer 1

The complexes which involve sp³d² hybridisation are called outer orbital complexes. This is due to the fact that they require the participation of outer d-orbitals, specifically the nd-orbitals of the central metal atom or ion, during the hybridisation process. The quantity of unpaired electrons in these complexes is comparatively higher. Therefore, they are also known as spin-free complexes or high-spin complexes.