Geneva nomenclature

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In chemistry - especially organic chemistry - the Geneva nomenclature is a historical system for the rational naming (naming) of chemical substances.

history

At a chemists' congress on the occasion of the World Exhibition in Paris in 1889 , the need for an understandable nomenclature or registration of organic substances was discussed. An international commission to which u. a. Adolf von Baeyer , Louis Bouveault , Stanislao Cannizzaro , Arthur Hantzsch , Emilio Noel Ting , Emanuele Paternò , Amé Pictet and later the German-Russian chemist Friedrich Konrad Beilstein included, came after some preliminary work from 19 to 22 April 1892 in Geneva together and adopted a number of nomenclature rules.

Result

The Geneva conference resolved around 60 points, which were published in detail in the reports of the German Chemical Society . These rules formed an important basis for later defined standards, right up to the IUPAC nomenclature used today .

Resolutions made
  1. In addition to the common names, an official name is to be introduced for each organic compound, which allows the compound in question to be found at a certain point in the registers and chemical handbooks. In order to facilitate such a registration, the authors of chemical treatises are asked to use the official names in parenthesis in addition to the designations they have chosen.
  2. The Congress has therefore decided to initially determine only the nomenclature of organic compounds of known constitution and to postpone the question of naming bodies of unknown constitution.
  3. The suffix "an" is used to denote the saturated hydrocarbons.
  4. The previous names of the first four saturated normal hydrocarbons: methane, ethane, propane, butane are retained, but the names of the higher members of this series are derived exclusively from the Greek numerals and accordingly the normal homologues of butane are designated as pentane, hexane, heptane, etc.
  5. The branched chain hydrocarbons are considered to be descendants of normal hydrocarbons. In this case, the name is formed by adding the name of the longest normal hydrocarbon, which can be assumed in the hydrocarbon with a branched chain, to the name of the hydrocarbon radical present in the side chain.
  6. If the side chain is also branched, then the name of the same is also formed according to the principle explained in sub V, only the alkyls of the side chain are given the final letter "o" instead of the final syllable "yl" and accordingly z. B. methyl and ethyl referred to as metho- and etho-
  7. The position of the side chains is indicated by numbers which indicate which carbon atoms of the main chain the side chains are connected to. The numbering begins at the end of the main chain that is closest to a side chain. If there are two symmetrical side chains on the main chain, counting starts at the end of the main chain which is closest to the lower-carbon or most simply composed side chain.
  8. The carbon atoms of the side chain are counted from the junction of the side chain with the main chain. The resulting numbers are added as indices to the number of the carbon atom of the main chain to which the side chain is attached.
  9. If two side chains adhere to one and the same carbon atom of the main chain, the side chain of lower order, ie of the lowest carbon or the simplest composition, is placed in front of the name. If existing substituting atoms or groups of atoms make it necessary to number the carbon atoms in one of these side chains, this is done in the manner explained under VIII, but the carbon atoms of the lower order side chain are given an accent in this case.
  10. In the same way, starting from the junction, the side chains that adhere to closed atomic chains must also be numbered.
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Individual evidence

  1. ↑ Ferd. Tiemann : On the resolutions of the international congress, which met in Geneva from April 19 to 22, 1892, for the regulation of chemical nomenclature . In: Reports of the German Chemical Society . tape 26 , no. 2 , 1893, p. 1595–1631 , doi : 10.1002 / cber.18930260283 ( PDF ).
  2. ↑ Wolfgang Holland: The nomenclature in organic chemistry. 2nd edition, VEB Deutscher Verlag für Grundstoffindustrie, 1973, pp. 14-17.