The Crystal Field Theory (CFT) to coordination compounds is based on
the effect of different crystal fields (provided by the ligands taken as point charges),
For example, impure nickel is converted to [Ni(CO)4], which is
decomposed to yield pure nickel •
Coordination compounds are of great importance in biological
systems The pigment responsible for photosynthesis, chlorophyll,
is a coordination compound of magnesium Haemoglobin, the red
pigment of blood which acts as oxygen carrier is a coordination
compound of iron