Which of the following is not correct for crystal field theory ?

Options

A. The crystal field theory (CFT) was originally proposed for explaining the optical properties of crystallise solids.
B. Cft assume the ligands to be point charges.
C. The interaction between the ligands and the electrons of the central metal is assumed to be covalent in nature.
D. The interaction between the ligand and the central metal atom/ion results in splitting of the d orbital energies.

Answer

C

Explanation

CFT is an electrostatic model which considers the metal-ligand bond to be ionic arising purely form electrostatic interations between the metal ion and the ligand. The five d orbitals in an isolated (gaseous state) metal atom/ion have same energy, i.e., they are degenerate. This degeneracy is maintained if a spherically symmetrical field of negative charges surrounds the metal atom/ion. However, when this negative field is due to ligands (either aninons or the negative ends of dipolar molecules like `NH_(3) H_(2)O`, etc.) in a complex, it becomes asymmetrical and the degeneracy of the d orbitals is lifted. The pattern of splitting depends upon the nature of the crystal field.