Question

If the crystal field splitting energy of a tetrahedral complex $\left(\Delta_{t}\right)$ of the type $\left[M L_{4}\right]^{n+}$ is $x \,eV$, what is the crystal field splitting energy with respect to an octahedral complex, [ $M L_{6}$ ] $^{n+}$ ?

• A. $\frac{9 x}{4} eV$
• B. $\frac{9 x}{8} eV$
• C. $\frac{4 x}{9} e V$
• D. $\frac{4 x}{5} e V$

Answer 1

Answer: (A)

The crystal field splitting in the tetrahedral field is smaller than in the octahedral field.

For most purposes the relationship between tetrahedral and octahedral crystral field splitting may be represented as :

$\Delta_{t}=\frac{4}{9} \Delta_{o} ; \Delta_{o}=\frac{9}{4}\left(\Delta_{t}\right)$

If the CFSE of tetrahedral complex $\left(\Delta_{t}\right)$ of

$\left[M L_{4}\right]^{n+}$ is $x eV$, the CFSE of octahedral complex

$\left[M L_{6}\right]^{n+}$ will be $\Delta_{o}=\frac{9 x}{4}$.