Pyridinium refers to the cationic form of pyridine. This can either be due to protonation of the ring nitrogen or because of addition of a substituent to the ring nitrogen, typically via alkylation. The lone pair of electrons on the nitrogen atom of pyridine is not delocalized, and thus pyridine can be protonated easily. Pyridine is often used as an organic base in chemical reations, thus the pyridinium ion is produced as the counter ion to the leaving group in the reaction. This complex is often insoluble in the organic solvent, so precipitation of the pyridinium leaving group complex is an indication of the progress of the reaction.The pyridinium ion also plays a role in Friedel-Crafts acylation. When pyridine is included, it forms a complex with the electrophillic acylium ion, rendering it even more reactive.

ee also

* Pyridinium chlorochromate

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  • Pyridinium — Ion pyridinium L ion pyridinium est l acide conjugué de la pyridine. Il s agit d un cation ayant pour formule brute C5H5NH+. La charge positive est portée par l atome d azote. Le pKa du couple pyridinium / pyridine est de 5,23. Formes mésomères… …   Wikipédia en Français

  • pyridinium — noun a) The cationic form of pyridine. b) An individual pyridinium cation …   Wiktionary

  • pyridinium — piridinis statusas T sritis chemija formulė Formulę žr. priede. priedas( ai) Grafinis formatas atitikmenys: angl. pyridinium rus. пиридиний …   Chemijos terminų aiškinamasis žodynas

  • Pyridinium chlorochromate — Chembox new Name = Pyridinium chlorochromate ImageFile = Pyridinium chlorochromate.png ImageSize = 150px ImageName = Chemical structure of the Pyridinium Chlorochromate ImageFileL1 = Pyridinium 3D balls.png ImageNameR1 = Ball and stick model of… …   Wikipedia

  • pyridinium chlorochromate — piridinio chlorchromatas statusas T sritis chemija formulė C₅H₅NClCrO₃H atitikmenys: angl. pyridinium chlorochromate rus. хлорхромат пиридиния …   Chemijos terminų aiškinamasis žodynas

  • pyridinium — A breakdown product of bone collagen, excreted in urine, and assayed as a measure of osteoclast activity; increased in disease states such as Paget s disease, primary hyperparathyroidism, and osteoporosis …   Medical dictionary

  • Pyridinium — Py|ri|di|ni|um, eigtl. Pyridin 1 ium [↑ Pyridin u. ↑ ium (2)], das; s: Bez. für das durch Anlagerung eines Protons an das Ring N Atom des Pyridins entstandene Kation C5H6N+; Pyridiniumchlorid z. B. ist eine ↑ Oniumverbindung. Vgl. Pyridylium …   Universal-Lexikon

  • pyridinium — pyr·i·din·i·um …   English syllables

  • pyridinium — ˌpirəˈdinēəm noun ( s) Etymology: New Latin, from International Scientific Vocabulary pyridine + New Latin ium : a univalent ion [C5H5NH]+ or radical C5H6N that is analogous to ammonium and is derived from pyridine …   Useful english dictionary

  • Chlorochromate De Pyridinium — Général Nom IUPAC chlorochromate de pyridinium …   Wikipédia en Français

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