Meta- (chemistry)

Ortho-meta-para.svg

In chemistry, meta is a prefix, used for systematic names in IUPAC nomenclature. It has several meanings.[1]

  • In organic chemistry, meta indicates the positions of substituents in aromatic cyclic compounds. The substituents have the 1,3-positions, for example in resorcinol.
  • Meta may also denote the dehydrated form of an acid, salt or organic derivative in a series. For example:
    • metabisulfite: 2 bisulfite (HSO
      3
      ) → 1 metabisulfite S
      2
      O2−
      5
      + H
      2
      O
    • metaphosphoric acid: 3 orthophosphoric acid H
      3
      PO
      4
      → 1 trimetaphosphoric acid (H
      3
      P
      3
      O
      9
      ) + 3 H
      2
      O
      .
    • Meta-antimonic acid, the dehydrated form of antimonic acid (H
      3
      SbO
      4
      ), is HSbO
      3
      .[2]

See also

  • Arene substitution patterns

References

  1. ^ "Definition of meta-". www.dictionary.com. 2016-02-10. Retrieved 2019-10-03.
  2. ^ Kern, Sergius (1875-02-19). Crookes, William (ed.). "New Method of Quantitative Analysis of Ordinary Alloys". Chemical News and Journal of Industrial Science. London: Chemical news office. XXXI (795): 76.

Media files used on this page

Ortho-meta-para.svg
Ortho-, meta- and para- positions of a phenyl group, with respect to a substituent group "G". Made with the free software program ChemTool, and fine-tuned editing by hand with Vim (text editor).