Sodium ammonium tartrate

Sodium ammonium tartrate (NAT) is an organic compound with the formula Na(NH₄)[O₂CCH(OH)CH(OH)CO₂]. The salt is derived from tartaric acid by neutralizing with ammonia and with sodium hydroxide. Louis Pasteur obtained enantiopure crystals of the tetrahydrate of NAT, via the process of spontaneous resolution.^[1] His discovery led to increased study of optical activity, which eventually was shown to have broad implications.^[2] Many modifications of this salt have been investigated by X-ray crystallography, including the racemate, which crystallizes as the monohydrate.^[3]

Sodium ammonium tartrate

Names
IUPAC name 2,3-Dihydroxybutanedioic acid, monoammonium monosodium salt
Other names Ammonium Rochelle salt
Identifiers
CAS Number	(L): 16828-01-6
3D model (JSmol)	(D/L): Interactive image
ChemSpider	(D/L): 10667488
ECHA InfoCard	100.037.121
EC Number	(L): 240-850-1
PubChem CID	(D/L): 21915779
CompTox Dashboard (EPA)	DTXSID90937472
InChI (D/L): InChI=1S/C4H6O6.H3N.Na/c5-1(3(7)8)2(6)4(9)10;;/h1-2,5-6H,(H,7,8)(H,9,10);1H3;/q;;+1/p-1 Key: QGKIJYBOYMJGHT-UHFFFAOYSA-M
SMILES (D/L): C(C(C(=O)[O-])O)(C(=O)[O-])O.[NH4+].[Na+]
Properties
Chemical formula	C4H8NNaO6
Molar mass	189.099 g·mol−1
Appearance	White solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Related compounds

• NaKO₂CCH(OH)CH(OH)CO₂(H₂O)₄, known as Rochelle salt, was the first ferroelectric material discovered.

References

1. L. Pasteur (1849). "Nouvelles recherches de L. Pasteur sur les relations qui peuvent exister entre la forme cristalline, la composition chimique et le phénomène de la polarisation rotatoire". Compt. Rend. 28: 477.
2. Brożek, Z.; Mucha, D.; Stadnicka, K. (1994). "X-ray Rietveld structure determination of ammonium Rochelle salt at 120 (Paraelectric phase) and 100 K (Ferroelectric phase)". Acta Crystallographica Section B Structural Science. 50 (4): 465–472. doi:10.1107/S0108768194000479.
3. Kuroda, Reiko; Mason, Stephen F. (1981). "Crystal structures of dextrorotatory and racemic sodium ammonium tartrate". Journal of the Chemical Society, Dalton Transactions (6): 1268. doi:10.1039/DT9810001268.