Importance of Chelates and Coordination Compounds.
Coordination compounds play an important role in the industry, analytical chemistry, plant, animal and human life. Following are some important aspects of chelates and coordination compounds:
- Chlorophyll, an important constituent of plants, is a chelate compound containing Mg+2 in the center linked with pyrrole nuclei.
- Hemoglobin, the red coloring matter of blood, is an iron chelate structurally similar to chlorophyll.
- Vitamin B12 os a cobalt complex linked with 5-deoxyadenosyl (5, 6- dimethyl benzimidazole) group.
- In analytical chemistry, chelating agents are becoming increasingly important For example, nickel is estimated with dimethylglyoxime through the formating of nickel-dimethylgyloxime complex. Chlorimetric determination of various metals is based on the complex formation. Chelating agents are frequently used as indicators in the titration of certain metal ions.
- An important use of chelating agents is for water softening Ion-exchange resins are used for this purpose based on coordination phenomena.
- Metal ion can be separated from the mixture based on the complex formation. The water-soluble chelates called sequestering agents are used in aqueous solution for the effective removal of objectionable metal ions. Ethylenediamine tetraacetic acid can be used to eliminate the harmful metal ions from the body.
- Coordination compounds are used in medicines, like detergents and antioxidants.
- They are used in dyeing and coloring agents.
- Invisible inks are mostly coordination compounds. For example, if we write with hydrate cobalt chloride and dry it, nothing would be visible. On keeping the paper near hot object the writing will become legible with a blue color. All this is due to the following changes in the complex compounds.
- Complex compounds are also widely used are catalysts in synthetic reactions. For example, Zieglar-Natta (after the name of professors who discovered it) catalyst is widely used in the polymerization of ethylene to from polyethylene. Similarly, (Ph3P) RhCl acts as a good catalyst for various reactions, i.e., polymerization hydroformylation, etc.