Pyridinium

Pyridinium refers to the cation [C5H5NH]+. It is the conjugate acid of pyridine. Many related cations are known involving substituted pyridines, e.g. picolines, lutidines, collidines. They are prepared by treating pyridine with acids.

Pyridinium
Names
Preferred IUPAC name
Pyridin-1-ium
Identifiers
3D model (JSmol)
ChemSpider
UNII
  • InChI=1S/C5H5N/c1-2-4-6-5-3-1/h1-5H/p+1 Y
    Key: JUJWROOIHBZHMG-UHFFFAOYSA-O Y
  • InChI=1S/C5H5N/c1-2-4-6-5-3-1/h1-5H/p+1
  • InChI=1S/C5H5N/c1-2-4-6-5-3-1/h1-5H/p+1
    Key: JUJWROOIHBZHMG-UHFFFAOYSA-O
  • c1cc[nH+]cc1
Properties
[C5H5NH]+
Molar mass 80.110 g·mol−1
Acidity (pKa) ~5
Conjugate base Pyridine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

As pyridine is often used as an organic base in chemical reactions, pyridinium salts are produced in many acid-base reactions. Its salts are often insoluble in the organic solvent, so precipitation of the pyridinium leaving group complex is an indication of the progress of the reaction.

Pyridinium cations are aromatic, as determined through Hückel's rule. They are isoelectronic with benzene.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.