Chapter 22, Problem 30QP

Interpretation Introduction

Interpretation:

The reason that crystal field splitting for an octahedral complex is always greater than that of a tetrahedral complex is to be explained.

Concept Introduction:

Crystal field splitting is defined as the difference in the energies between the lower-energy ($d_{xy}\text{, }{d}_{yz}\text{, and }{d}_{zx}$) and the higher-energy ($d_{x^2-y^2}\text{ and }{d}_{z^2}$) $d\text{ orbitals}$.

Complex ions have $4-7d\text{ electrons}$, out of which three electrons will enter the lower-energy orbitals but the remaining may either enter the lower-energy orbital(s) or the higher-energy orbital(s).

When the electrons enter the higher-energy orbital(s), that is, $d_{x^2-y^2}\text{ and/or }{d}_{z^2}$, high-spin complexes are formed. Weak ligands produce high-spin complexes. When electrons, in the presence of strong ligands, enter the lower-energy orbital(s), that is, $d_{xy}\text{, }{d}_{yz}\text{, and }{d}_{zx}$, they form low spin complexes.