Briefly explain the concept of -Crystal field theory.

Explanation

After the failure of the valence bond theory the crystal field theory was proposed äround .1950 .. The theory is based on the assumption that the ligands are considered to be point charges which interacts electrostatically with the central metal
atom/ion. It is assumed that the five d-orbitals of the isolated metal atom/ion to be symmetrically arranged and are degenerated (i.e. having same energy)., This degeneracy is maintained till symmetrical field of the charges surrounds them, but when the negative field is due to either anion ligands (or due to .the polarity of neutral ligands like .NH_3. ) it. becomes asymmetrical and the degenerated f-or- " bitals splits up. into two parts depending upon the field generated by ligands. This splitting of d-orbitals. is the basis of CFT.