The crystal field splitting,
Do, depends upon the field
produced by the ligand and
charge on the metal ion Some
ligands are able to produce
strong fields in which case, the
splitting will be large whereas
others produce weak fields
and consequently result in
small splitting of d orbitals In general, ligands can be arranged in a series in the order of increasing
field strength as given below:
I
– < Br
– < SCN
– < Cl
– < S
2– < F
– < OH
– < C2O4
2– < H2O < NCS
–
< edta
4– < NH3 < en < CN
– < CO
Such a series is termed as spectrochemical series It is an
experimentally determined series based on the absorption of light
by complexes with different ligands