Question

Which of the following is/are characteristic of a tetrahedral complex?

• A. $d_{x^2-y^2}$ and $d_{z^2}$ orbitals are lower energy orbitals
• B. The crystal field splitting is found to be approximately double in octahedral complexes
• C. Most of the tetrahedral complexes are low spin complexes
• D. The splitting pattern in tetrahedral complexes is just the opposite of those in the octahedral complexes

Answer 1

Answer: (A), (B), (D)

The correct options are
A $d_{x^2-y^2}$ and $d_{z^2}$ orbitals are lower energy orbitals
B The crystal field splitting is found to be approximately double in octahedral complexes
D The splitting pattern in tetrahedral complexes is just the opposite of those in the octahedral complexes

a) In tetrahedral complexes, $d_{x^2-y^2}$ and $d_{z^2}$ are lower energy orbitals, as in the tetrahedral complexes, the ligands do not approach along the axes.
b) Crystal field splitting is found to be approximately double in octahedral complexes because in the octahedral complexes more number of ligands (6) approach the central metal ion as compared to tetrahedral complexes.
c) Since the crystal field splitting is less in tetrahedral complexes, the pairing energy is often more than the energy required for the transition of electrons. Thus, most of tetrahedral complexes are high spin complexes.
d) Due to the ligands approaching along different directions, the splitting pattern in tetrahedral complexes is just the opposite of that in the octahedral complexes.