Racemic mixture

He manually separated the crystals of a mixture, starting from an aqueous solution of the sodium ammonium salt of racemate tartaric acid.

Reasoning from the macroscopic scale down to the molecular, he reckoned that the molecules had to have non-superimposable mirror images.

Carl von Linné gave red elderberry the scientific name Sambucus racemosa as the Swedish name, druvfläder, means 'grape elder', so called because its berries grow in a grape-like cluster.

[4][5] A racemate is optically inactive (achiral), meaning that such materials do not rotate the polarization of plane-polarized light.

This fact also leads to the question of how biological homochirality evolved on what is presumed to be a racemic primordial earth.

The reagents of, and the reactions that produce, racemic mixtures are said to be "not stereospecific" or "not stereoselective", for their indecision in a particular stereoisomerism.

A frequent scenario is that of a planar species (such as an sp2 carbon atom or a carbocation intermediate) acting as an electrophile.

The nucleophile will have a 50% probability of 'hitting' either of the two sides of the planar grouping, thus producing a racemic mixture: Some drug molecules are chiral, and the enantiomers have different effects on biological entities.

The original Benzedrine was a racemic mixture, and isolated dextroamphetamine was later introduced to the market as Dexedrine.

However, sometimes samples containing pure enantiomers may be made and sold at a higher cost in cases where the use requires specifically one isomer (e.g., for a stereospecific reagent); compare omeprazole and esomeprazole.