Ammonium Tartrate

Tartaric acid is noteworthy for a) the excellent way in which the majority of its salts Crystallise, and h) the frequent occurrence of salts having mixed cations. Examples of the latter are sodium potassium tartrate (or Rochelle salt), C4H40 NaK, used for the preparation of Fehling s solution (p. 525), sodium ammonium tartrate, C4H OaNaNH4, used by Pasteur for his early optical resolution experiments, and potassium antimonyl tartrate (or Tartar Emetic), C4H404K(Sb0). The latter is prepared by boiling a solution of potassium hydrogen tartrate (or cream of tartar ) with antimony trioxide,... 

Example. Heat together under reflux 0 5 g. of ammonium tartrate and i 5 ml. of benzylamine for i hour. Shake with water to remove the excess of benzylamine and filter off the benzylamide. Recrystallise from ethanol ... 

Add a few drops of acetic acid and a little ammonium or potassium acetate solution to a moderately strong solution of tartaric acid or a neutral tartrate. On stirring with a glass rod, the acid potassium or ammonium tartrate will be precipitated. 

Ammonium acetate Ammonium adipate Ammonium benzoate Ammonium bicarbonate Ammonium biflluoride Ammonium binoxalate Ammonium bisulfate Ammonium bitartrate Ammonium tetraborate Ammonium bromide Ammonium carbonate Ammonium chloride Ammonium citrate Ammonium diclnomate Ammonium fluoride Ammonium fluorosilicate Ammonium gluconate Ammonium iodide Ammonium molybdate Ammonium nitrate Ammonium oxalate Ammonium perchlorate Ammonium picrate Ammonium polysulfide Ammonium salicylate Ammonium stearate Ammonium sulfate Ammonium sulfide (hydrosulfide) Ammonium tartrate Ammonium tliiocyanate Ammonium thiosulfate... 

The optical activity of quartz and certain other materials was first discovered by Jean-Baptiste Biot in 1815 in France, and in 1848 a young chemist in Paris named Louis Pasteur made a related and remarkable discovery. Pasteur noticed that preparations of optically inactive sodium ammonium tartrate contained two visibly different kinds of crystals that were mirror images of each other. Pasteur carefully separated the two types of crystals, dissolved them each in water, and found that each solution was optically active. Even more intriguing, the specific rotations of these two solutions were equal in magnitude and of opposite sign. Because these differences in optical rotation were apparent properties of the dissolved molecules, Pasteur eventually proposed that the molecules themselves were mirror images of each other, just like their respective crystals. Based on this and other related evidence, in 1847 van t Hoff and LeBel proposed the tetrahedral arrangement of valence bonds to carbon. 

L. Pasteur (aged 26) began work on optically active sodium ammonium tartrate. 

Little was done after Biot s discovery of optical activity until 1848, when Louis Pasteur began work on a study of crystalline tartaric acid salts derived from wine. On crystallizing a concentrated solution of sodium ammonium tartrate below... 

Figure 9.6 Drawings of sodium ammonium tartrate crystals taken from Pasteur s original sketches. One of the crystals is "right-handed" and one is "left-handed."...

If aluminium is present, add 1 g of ammonium tartrate to the clear, slightly... 

Ever since Pasteur s work with enantiomers of sodium ammonium tartrate, the interaction of polarized light has provided a powerful, physical probe of molecular chirality [18]. What we may consider to be conventional circular dichroism (CD) arises from the different absorption of left- and right-circularly polarized light by target molecules of a specific handedness [19, 20]. However, absorption measurements made with randomly oriented samples provide a dichroism difference signal that is typically rather small. The chirally induced asymmetry or dichroism can be expressed as a Kuhn g-factor [21] defined as ... 

For generation of acidic conditions, a non-volatile acid such as citric acid (12.7), or an acid donor such as ammonium tartrate (12.8) or ammonium sulphate, is preferred. An acid or acid donor is not used with 1 2 metal-complex dyes of high neutral-dyeing affinity,... 

Figure 45. EL spectrum of anodic oxide film formed in an ammonium tartrate solution.

The manual separation of the enantiomorphous crystals of sodium ammonium tartrate tetrahydrate (Figure 1) by Pasteur in 1848 (1) is historically significant, because it laid the foundations of modem stereochemistry. This experiment demonstrated for the first time that certain classes of molecules display enan-tiomorphism even when dissolved in solvent. These observations eventually paved the way for the inspired suggestion, made more than two decades later, by van t Hoff (2) and Le Bel (3), of a tetrahedral arrangement of bonds around the carbon atom. 

Figure I. Enantiomorphous crystals of sodium ammonium tartrate -4H20.

Crystals composed of the R and S enantiomers of the same racemic mixture must be related by mirror symmetry in terms of both their internal structure and external shape. Enantiomorphous crystals may be sorted visually only if the crystals develop recognizable hemihedral faces. [Opposite (hid) and (hkl) crystal faces are hemihedral if their surface structures are not related to each other by symmetry other than translation, in which case the crystal structure is polar along a vector joining the two faces. Under such circumstances the hemihedral (hkl) and (hkl) faces may not be morphologically equivalent.] It is well known that Pasteur s discovery of enantiomorphism through die asymmetric shape of die crystals of racemic sodium ammonium tartrate was due in part to a confluence of favorable circumstances. In the cold climate of Paris, Pasteur obtained crystals in the form of conglomerates. These crystals were large and exhibited easily seen hemihedral faces. In contrast, at temperatures above 27°C sodium ammonium tartrate forms a racemic compound. 

Pasteur s salt solution analychem Laboratory reagent consisting of potassium phosphate and caicium phosphate, magnesium sulfate, and ammonium tartrate in distilled water. pa storz solt S3,lii-sh3n ... 

Mechanical Separation of Crystals. The first instance of resolution was by L. Pasteur who was able to resolve crystals of sodium ammonium tartrate (which recrystallizes in two distinct, nonsuperimposable forms below 2TC). Although this procedure is rarely used, one might be able to seed a racemic solution resulting in only one... 

Ammonium Oxalate Ammonium Oxalate Hydrate Ammonium Pentaborate Ammonium Pentaborate Tetrahydrate Ammonium Pentachlorozincate Ammonium Perchlorate Ammonium Peroxydisulfate Ammonium Persulfate Ammonium Phosphate Ammonium Phosphate, Dibasic Ammonium Rhodanate Ammonium Rhodanide Ammonium Silicofluoride Ammonium Stearate Ammonium Sulfamate Ammonium Sulfate Ammonium Sulfhydrate Solution Ammonium Sulfide Ammonium Sulfide Solution Ammonium Sulfite Ammonium Sulfocyanate Ammonium Sulfocyanide Ammonium Tartrate Ammonium Thiocyanate Ammonium Thiosulfate Ammonium Zinc Chloride Amorphous Phosphorus AMS... 

Naphthalene, Molten Antimony Potassium Tartrate Ammonium Tartrate Antimony Potassium Tartrate Antimony Potassium Tartrate Tert-Butylamine Tricresyl Phosphate Calcium Phosphate DDD... 

Ammonium Tartrate — Fire Hazards Flash Point (deg. F) Not pertinent (combustible solid) Flammable Limits in Air (%) Not pertinent Fire Extinguishing Agents Water Fire Extinguishing Agents Not To Be Used Not pertinent Special Hazards of Combustion Products Toxic oxides of nitrogen or ammonia gas may form in fires Behavior in Fire Not pertinent Ignition Temperature (deg. F) Not pertinent Electrical Hazard Not pertinent Burning Rate Not pertinent. Chemical... 

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