Nitrilotriacetic acid

Nitrilotriacetic acid

Skeletal formula of nitrilotriacetic acid
Names
Preferred IUPAC name 2,2′,2′′-Nitrilotriacetic acid
Systematic IUPAC name 2-[Bis(carboxymethyl)amino]acetic acid
Other names Triglycine
Identifiers
CAS Number	139-13-9 Y
Beilstein Reference	1710776
ChEBI	CHEBI:44557 Y
ChemSpider	8428 Y
DrugBank	DB03040 Y
EC Number	205-355-7
Gmelin Reference	3726
Jmol 3D model	Interactive image Interactive image
KEGG	C14695 N
MeSH	Nitrilotriacetic+Acid
PubChem	8758
RTECS number	AJ0175000
UN number	2811
InChI InChI=1S/C6H9NO6/c8-4(9)1-7(2-5(10)11)3-6(12)13/h1-3H2,(H,8,9)(H,10,11)(H,12,13) Y Key: MGFYIUFZLHCRTH-UHFFFAOYSA-N Y
SMILES [o]:c(:[oH])CN(Cc(:[o]):[oH])Cc(:[o]):[oH] OC(=O)CN(CC(O)=O)CC(O)=O
Properties
Chemical formula	C6H9NO6
Molar mass	191.14
Appearance	White crystals
Melting point	246 °C (475 °F; 519 K)
Solubility in water	Insoluble. <0.01 g/100 mL at 23℃
Thermochemistry
Std enthalpy of formation (ΔfHo298)	−1.3130–−1.3108 MJ mol−1
Vapor pressure	{{{value}}}
Related compounds
Related alkanoic acids	EDTA Iminodiacetic acid EDDS
Related compounds	Triethanolamine Tris(2-aminoethyl)amine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Nitrilotriacetic acid (NTA) is the aminopolycarboxylic acid with the formula N(CH₂CO₂H)₃. It is a colourless solid that is used as a chelating agent, which forms coordination compounds with metal ions (chelates) such as Ca²⁺, Cu²⁺, and Fe³⁺.

Production and use

Nitrilotriacetic acid is commercially available as the free acid and as the sodium salt. It is produced from ammonia, formaldehyde, and sodium cyanide or hydrogen cyanide. Worldwide capacity is estimated at 100 thousand tonnes per year.

The acid is also cogenerated as an impurity in the synthesis of EDTA, arising from reactions of the ammonia coproduct.

Coordination chemistry and applications

The uses of NTA are similar to that of EDTA, both being chelating agents. In contrast to EDTA, NTA is easily biodegradable and is almost completely removed during wastewater treatment. It is used for water softening and as a replacement to sodium and potassium triphosphate in detergents, and cleansers. NTA is a tripodal tetradentate trianionic ligand. In the laboratory, this compound is used in complexometric titrations. A variant of NTA is used for protein isolation and purification in the His-tag method. The modified NTA is used to immobilize nickel to a solid support. This allows purification of proteins containing a tag consisting of six histidine residues at either terminus.

• NTA complexes
• Ni(NTA)(aq)23views.png

  Three views of the structure of [Ni(NTA)(H₂O)₂]⁻.

• Calcium complex of NTA trianion.svg

  Structure of the [Ca(NTA)(H₂O)₃]⁻.