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Chelation (/ k iː ˈ l eɪ ʃ ən /) is a type of bonding of ions and their molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom.
A concentrated solution of metals is obtained by eluting the resin with a small volume of 2 M nitric acid, which protonates the iminodiacetate groups. Chelex resin is often used for DNA extraction in preparation for polymerase chain reaction by binding to cations including Mg 2+ , which is an essential cofactor for DNases .
EGTA (ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid), also known as egtazic acid (INN, USAN), [2] is an aminopolycarboxylic acid, a chelating agent. It is a white solid that is related to the better known EDTA. Compared to EDTA, it has a lower affinity for magnesium, making it more selective for calcium ions.
The chelate effect increases as the number of chelate rings increases. For example, the complex [Ni(dien) 2)] 2+ is more stable than the complex [Ni(en) 3)] 2+; both complexes are octahedral with six nitrogen atoms around the nickel ion, but dien (diethylenetriamine, 1,4,7-triazaheptane) is a tridentate ligand and en is bidentate. The number of ...
Microbes usually release the iron from the siderophore by reduction to Fe 2+ which has little affinity to these ligands. [8] [2] Siderophores are usually classified by the ligands used to chelate the ferric iron. The major groups of siderophores include the catecholates (phenolates), hydroxamates and carboxylates (e.g. derivatives of citric ...
A linear tetradentate ligand has the four donor atoms in a line and each subsequent donor is connected by one of three bridges. Such a ligand bound to a metal in tetrahedral coordination can only connect in one way, though if the ligand is unsymmetrical then there are two chiral arrangements.
Chelating resins are a class of ion-exchange resins.They are almost always used to bind cations, and utilize chelating agents covalently attached to a polymer matrix. Chelating resins have the same bead form and polymer matrix as usual ion excha
EDDHA or ethylenediamine-N,N ′-bis(2-hydroxyphenylacetic acid) is a chelating agent. Like EDTA, it binds metal ions as a hexadentate ligand, using two amines, two phenolate centers, and two carboxylates as the six binding sites. The complexes are typically anionic. The ligand itself is a white, water-soluble powder.