Chelating agents are the organic compounds which form multiple bonds with single metal ion. The compound thus formed by a chelating agent and a metal ion is called a Chelate. (5)
These chelating agents are also called ligands, chelants, chelators or sequestering agents. (1)
- It forms stable ring structures with metal ions.(6)
- It is used to reduce the metal ions concentration in solution.(6)
In chelate the chelating agent is an electron pair donor and metal is electron pair acceptor.Thus the bonding between them is a coordinate covalent bond. (5)
Based on the capability of ligand to donate no of pair of electrons they are classified as:
- Monodentate:contain one donor electron
- Bidentate: contain two donor electrons. And so on. Examples :( 2)
1) Most commonly used chelating agent is EDTA i.e. Ethylene diamine tetra acetic acid. EDTA has wide uses:
- Antidote for lead poisoning
- For separation of rare earth elements from each other.
- For enhancing cleaning power of detergents and soaps
2) Ethylene diamine is also a versatile chelating agent.
3) Other important chelating agent found in biological system is porphine.It form complex with iron to form heme group.
4) Dimercaprol: chelating agent for heavy metals like arsenic, mercury, gold and antimony.
Applications :( 1), (3)
- Chelating agents like Histidine,malate and phytochelatin are found in plants
- Chemical weathering is due to chelating agents.
- Used in chemical analysis as water softeners.
- Chelating agents are used to detoxify various metal poisons like mercury, arsenic, lead etc.
- EDTA is used in root canal treatment
- Gadolinium complexes are used as contrast agents in MRI scans.
- Used in photography, in chemical plating, in electroplating, in textile dyeing, as additives in plastics and in food and paper industry.
This blog do not contain any plagiarized matter
1) en.wikipedia.org/wiki/Chelation -