Discuss briefly giving an example in each case the role of coordination compounds in:

(i) biological systems (iii) analytical chemistry

(ii) medicinal chemistry and (iv) extraction/metallurgy of metals.

(i) Role of coordination compounds in biological system:

We know that in the process of photosynthesis, sunlight is absorbed by the plants through a green pigment called as chlorophyll. This chlorophyll is a co-ordination compound of magnesium. In our human biological body, coordination compounds play a major role. In our blood the oxygen carrier i.e hemoglobin is a co-ordination compound of iron.

(ii) In medicinal chemistry:

A co-ordination compound of platinum called as cis-platin is used in the treatment of stopping the growth of the tumour in our body.

(iii) In analytical chemistry:

In the analysis of salt , when different reagents containing ligands are added to different basic radicals they form coordination compounds. These coordination compounds exhibit different colours associated with each of the basic radicals. Thus it can be used in detection of various radicals.

(iv) In extraction or metallurgy of metals:

In the extraction of the metals from their ores the ability of the metals to form complexes or coordination comppunds are used. For eg. In aqueous solution, gold combines with the cyanide ions to form a complex. Later gold can be extracted from this complex by treating it with zinc metal.