Such a repulsion is more when the metal d orbital is directed towards
the ligand than when it is away from the ligand Thus, the 
2
2
x
y
d
and
dz2
 orbitals which point towards the axes along the direction of
the ligand will experience more repulsion and will be raised in
energy; and the dxy, dyz and dxz orbitals which are directed between
the axes will be lowered in energy relative to the average energy in
the spherical crystal field Thus, the degeneracy of the d orbitals
has been removed due to ligand electron-metal electron repulsions
in the octahedral complex to yield three orbitals of lower energy, t2g
set and two orbitals of higher energy, eg set This splitting of the
Rationalised 2023-24
132
Chemistry
degenerate levels due to the
presence of ligands in a
definite geometry is termed as
crystal field splitting and
the energy separation is
denoted by Do (the subscript
o is for octahedral) (Fig