Why can't there be any low spin tetrahedral complex?

Explanation

The extent of d - orbital in a tetrahedral crystal field is much less and hence, the value of crystal field splitting energy `(Delta_(t))` is very small. The value of pairing energy is always greater than `Delta_(t)` is very small. The value of pairing energy is always greater than `Delta_(t)` [i.e., `(P gt Delta_(t))`] and hence, in the d - orbitals of the metal ions, pairing of electrons hardly takes place. Therefore, in the presence of tetrahedral field, the metal ions seldom form low spin complexes. Two types of electronic configuration are shown for a `d^(5)` ion.