Carl Friedrich Naumann and the introduction of enantio terminology: a review and analysis on the 150th anniversary.

Enantiomorphism and enantiomorphous were the first enantio-based terms, introduced 150 years ago, by Carl Friedrich Naumann, a German crystallographer, to refer to non-superposable mirror-image crystals. The terminology was not adopted by Pasteur, the discoverer of molecular chirality, and was not embraced at first in the stereochemical context, until it was accepted in 1877 by Van't Hoff in the German edition of his proposal for the tetrahedral asymmetric carbon atom. In the 1890s the use of enantio terms began to spread in the research literature, and many new derivatives of Naumann's original two terms were subsequently introduced. Problems in the usage of some of the terms are often found in the literature, e.g., enantiomorphism is sometimes confused with chirality; enantiomeric is often misused; the meaning of some of the many derived terms, e.g., enantiosymmetric, enantioposition, etc., is unclear. All in all, Naumann should be remembered as the creator of essential terminology in the realm of chirality.