Question

Increasing order of crystal field splitting power of the following ligands:
(A) CN$^-$
(B) Cl$^-$
(C) F$^-$
(D) H$_2$O
Choose the correct answer from the options given below:

• A. A $<$ B $<$ C $<$ D
• B. A $<$ C $<$ B $<$ D
• C. A $<$ D $<$ C $<$ B
• D. B $<$ C $<$ D $<$ A

Answer 1

Answer: (D)

B $<$ C $<$ D $<$ A

Answer 2

Ligands are classified as strong or weak field ligands based on their ability to split the d-orbital energies in a metal complex. Cl$^-$ is a weak field ligand, followed by F$^-$, H$_2$O (which is a moderate field ligand), and CN$^-$ is a strong field ligand.
This leads to the increasing order of crystal field splitting power: $Cl^− ¡ (C) F^− ¡ (D) H_2O ¡ (A) CN^−$