Racemic acid

Racemic acid is an old name for an optically inactive or racemic form of tartaric acid. It is an equal mixture of two mirror-image isomers (enantiomers), optically active in opposing directions.

Its sodium-ammonium salt is unusual among racemic mixtures in that during crystallization it can separate out into two kinds of crystals, each composed of one isomer, and whose macroscopic shapes are mirror images of each other. Thus, Louis Pasteur was able to separate the two enantiomers by picking apart the crystals.[1][2]

In a modern-time re-enactment of the Pasteur experiment,[3][4] it was established that the preparation of crystals was not very reproducible. The crystals deformed, but they were large enough to inspect with the naked eye (microscope not required).

See also

References

  1. Pasteur announced his intention to resolve racemic acid in: Pasteur presents his resolution of racemic acid into separate optical isomers in:
  2. George B. Kauffman & Robin Myers (1998). "Pasteur's Resolution of Racemic Acid: A Sesquicentennial Retrospect and a New Translation" (PDF). The Chemical Educator. 3. doi:10.1007/s00897980257a. Archived from the original (PDF) on 2006-01-17.
  3. Yoshito Tobe (2003). "The reexamination of Pasteur's experiment in Japan" (PDF). Mendeleev Communications Electronic Version (3). doi:10.1070/MC2003v013n03ABEH001803. Archived from the original (PDF) on August 31, 2005.
  4. Masao Nakazaki (1979). "Morphology of sodium ammonium tartrate: Pasteur's spontaneous resolution and its reexamination". Kagaku no Ryoiki. 33: 951–962.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.