What is a chelate?

A chelate is an organic compound that is made up of several ligands bound around a metal atom. According to IUPAC, chelation is defined as the formation of two or more coordinate bonds between a ligand and a central atom . The ligands are called chelating agents, chelating agents, or sequestering agents. In the image we see a component of hemoglobin in which the heme B group acts as an iron chelating agent.

Use of chelates

Chelates are used to neutralize the toxic effect of certain metals, such as heavy metals. Chelation is used to make nutritional supplements and fertilizers, as well as to prepare MRI catalysts and contrast compounds.

example of chelates

• Many biochemical molecules can incorporate metal cations forming chelates. Nucleic acids, proteins, amino acids, polypeptides, and polysaccharides act as binding agents to form chelates.
• Ethylenediamine is a chelating agent that forms a five-component ring-shaped complex with the copper ion, CuC ₂ N ₂ .
• Almost all metalloenzymes are chelating agents for various metals.
• Chemical weathering is caused by organic chelants that extract metal ions from rocks and minerals.
• Many nutritional supplements are prepared by chelating metal ions to help protect the metal from complexing with insoluble salts in the stomach. In this way the supplements provide a greater absorption capacity of the metal.
• Many catalysts are produced by chelation, such as ruthenium(II) chloride produced by chelation with a phosphine.
• EDTA and phosphonates are chelating agents used in various applications, such as hard water purification.