The magnitude of crystal field stabilisation energy (CFSE of `Delta_(1)`) in tetrahedral complexes is considerably less than that in the octahderal field. Because

Options

A. There are only four ligands instead of six so the ligand field is only 2/3 the size hence the `Delta_t` is 2/3
B. The direction of the orbitals does not coincide with the direction of the ligands. This reduces the crystal field stabilization energy `(Delta)` by further 2/3
C. Both points (a) and (b) are correct
D. Both points (a) and (b) are wrong

Answer

C

Explanation

In tetrahedral complex formation, the d–orbital splitting is inverted and smaller as compared to the octahedral field splitting. There are only four ligands instead of six and the direction of the orbitals does not coincide with the direction of the ligands. If `Delta_t` and `Delta_0` are the magnitude of energy separation in tetrahedral and octahedral complexes, then `Delta_t = (-4//9)Delta_0` .