Sodium ammonium tartrate

{{Chembox

| ImageFile = Sodium ammonium tartrate.svg

| ImageSize = 200px

| ImageAlt =

| IUPACName = 2,3-Dihydroxybutanedioic acid, monoammonium monosodium salt

| OtherNames = Ammonium Rochelle salt

|Section1={{Chembox Identifiers

| index1_label = (D/L)

| index2_label = (D)

| index3_label = (L)

| CASNo3 = 16828-01-6

| ChemSpiderID1 = 10667488

| EC_number3 = 240-850-1

| PubChem1 = 21915779

| InChI1=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

| InChIKey1 = QGKIJYBOYMJGHT-UHFFFAOYSA-M

| SMILES1 = C(C(C(=O)[O-])O)(C(=O)[O-])O.[NH4+].[Na+]

}}

|Section2={{Chembox Properties

| C = 4|H=8|O=6|Na=1|N=1

| MolarMass =

| Appearance = White solid

| Density =

| MeltingPt =

| MeltingPt_notes =

| BoilingPt =

| BoilingPt_notes =

| Solubility = }}

|Section3={{Chembox Hazards

| MainHazards =

| FlashPt =

| AutoignitionPt = }}

}}

Sodium ammonium tartrate (NAT) is an organic compound with the formula {{chem2|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.{{cite journal|author=L. Pasteur|journal=Compt. Rend.|year=1849|volume=28|page= 477|title=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}} His discovery led to increased study of optical activity, which eventually was shown to have broad implications.{{cite journal |doi=10.1107/S0108768194000479 |title=X-ray Rietveld structure determination of ammonium Rochelle salt at 120 (Paraelectric phase) and 100 K (Ferroelectric phase) |date=1994 |last1=Brożek |first1=Z. |last2=Mucha |first2=D. |last3=Stadnicka |first3=K. |journal=Acta Crystallographica Section B Structural Science |volume=50 |issue=4 |pages=465–472 }} Many modifications of this salt have been investigated by X-ray crystallography, including the racemate, which crystallizes as the monohydrate.{{cite journal |doi=10.1039/DT9810001268 |title=Crystal structures of dextrorotatory and racemic sodium ammonium tartrate |date=1981 |last1=Kuroda |first1=Reiko |last2=Mason |first2=Stephen F. |journal=Journal of the Chemical Society, Dalton Transactions |issue=6 |page=1268 }}