What is meant by stability of coordinate compound in solution? State the factors which govern stability of complexes.
Biological system:
(i) Haemoglobin the red blood cell which acts as oxygen carrier to different parts of the body is a complex of iron(II).
(ii) Vitamin B12 is a complex of cobalt metal. Trace metals also function through coordination processes.
(iii) A complex of zinc(II) called enzyme CPA helps in digestion of food.
(iv) The chlorophyll, the green colouring plant pigment that plays an important role in photosynthesis is a complex of magnesium. In chlorophyll Mg is coordinated to four nitrogens of porphyin units.