Question

What is meant by crystal field splitting energy? On the basis of crystal field theory, write die electronic configuration of d⁴ in terms of t_2g and e_g in an octahedral field when

(i) D₀ > P
(ii) D₀ < P

Answer 1

Crystal field splitting energy: In an octahedral field, when ligands approach to the central metal ion to form coordination bonds, the five degenerated d-obitals of central metal ion splits in two sets of orbitals having different energies. This splitting of degenerated d-orbitals is called central field splitting and the energy difference between two sets of orbitals is called crystal field splitting energy (CFSE, ∆₀)

• ∆ > P, (pairing energy), the 4th electron pair up in one of the t_2g or bitals giving the configuration t_2g⁴ e_g⁰ J.
• If ∆₀ > P the 4th electron enters one of the eg orbitals giving the configuration t_2g³ e_g¹.