Splitting In Tetrahedral complexes:-

Four legands attack from alternate diagonal (alternate tetrahedral void

Since number of legands and number of attacking direction both are 2/3 rd

So t = 4/9 _o

Splitting in square planar complex or John-Teller Distortion;

 

ΔS = 1.3 Δ_o

Imp:- ΔS > Δ_o > Δt

Octahedral:- dx² – y² = dz² > dxy = dyz = dxz

Tetrahedral:- dxy = dyz > dzx > dx² – y² = dz²

Square planar:- dx² – y² > dxy > dz² > dyz = dzx

e.g.:-

a) [Ni (CN)₄ ]^-2

dsp², square planar

diamagnetic,      μ = 0

Note Exception:-

1. [Co (NH₃) ]⁺²                      d²SP³,    paramagnetic

Co+2 = 45°3d⁷ 

2) [Cu (NH₃)₄ ]⁺²                    dsp²