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 nitrogenatom 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. Chemical structure of the pyridinium cation Selfmade by cacycle File links The following pages link to this file: Pyridine Pyridinium Categories: GFDL images ... In chemistry, a cationic species is one that contains a full positive charge. ... Pyridine is a chemical compound with the formula C5H5N. It is a liquid with a distinctively sour odour. ... Protonation is the addition of a proton (H+) to an atom, molecule, or ion. ... Alkylation is the transfer of an alkyl group from one molecule to another. ... A lone pair is an electron pair without bonding or sharing with other atoms. ... The Electron is a fundamental subatomic particle that carries an electric charge. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... Properties In chemistry and physics, an atom (Greek ἄτομος or átomos meaning indivisible) is the smallest particle of a chemical element that retains its chemical properties. ... In chemistry, delocalized electrons are electrons in a molecule that do not belong to a single atom or a covalent bond. ... An ion is an atom or group of atoms that normally are electrically neutral and achieve their status as an ion by loss or addition of one or more electrons. ... Insoluble Not soluble ... The Friedel-Crafts reactions were developed by Charles Friedel and James Crafts in 1877. ...
see also: pyridinium chlorochromate Pyridinium chlorochromate, a reddish orange solid reagent, is used to oxidize primary alcohols to aldehydes and secondary alcohols to ketones. ...
Pyridine is often used as an organic base in chemical reations, thus the pyridiniumion 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.
A composition in accordance with claim 1 wherein the resin used is a styrene copolymer of n-butyl methacrylate, the pigment used is carbon fl and the alkyl pyridinium compound used is cetyl pyridinium chloride.
The alkyl pyridinium compounds and their hydrates can be used in any amount that results in toner that is charged positively in comparison to the carrier and that develops and electrostatically transfers well.
Toner C comprising 6 percent of cetyl pyridinium chloride treated Regal 330 carbon fl, 1 percent of cetyl pyridinium chloride and 93 percent styrene/n-butyl methacrylate 65/35 copolymer resin was prepared by melt blending folowed by mechanical attrition.
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