Ammonium Compounds Rule C-816

Salts and hydroxides containing quadricovalent nitrogen, (where the R's may be the same or different), are named by one of the following methods:

816.1 - The compound is named as a substituted ammonium salt or hydroxide; the names of the substituting radicals precede the word "ammonium" and then the name of the anion is added.

Examples to Rule C-816.1


The following names are retained for the unsubstituted compounds:

816.2 - When the compound can be considered as derived from a base whose name does not end in "-amine", its quaternary nature is denoted by adding "-ium" to the name of that base, with elision of terminal "e" if present; substituent groups are cited as prefixes, and the name of the anion is added at the end.

Examples to Rule C-816.2

816.3 - In complex cases, the prefixes "amino-" and "imino-" may be changed to "ammonio-" and "iminio-" and are followed by the name of the molecule representing the most complex group attached to this nitrogen atom and preceded by the names of the other radicals attached to this nitrogen atom; finally the name of the anion is added (see also Rules C-85 and C-87).

Examples to Rule C-816.3

or, by Rule C-816.1, 1-Acridinyltrimethylammonium chloride

816.4 - When the above rules cannot be applied or lead to inconvenient names, recourse may be had to two traditional methods of naming salts of organic bases, namely: (a) the unaltered name of the base is followed by the name of the anion; and (b), for salts of hydrohalogen acids only, the unaltered name of the base is followed by hydrofluoride, hydrochloride, hydrobromide, or hydriodide, as the case may be. These methods are retained for use also in simpler cases but the procedure of Rule C-816.2 is preferred.

Examples, where the structure is indefinite and Rule C-816.2 thus cannot be applied:

816.5 - Complexes formed from bases and phenols are named by citing the name of the base followed by that of the phenol in its anion form.

Examples to Rule C-816.5

Aniline picrate C6H5NH2,C6H3N3O7
Indole styphnate C8H7N,C6H3N3O8

See Recommendations'93 R-5.4

Amides and Imides C-821, C-822, C-823, C-824, C-825, C-826, C-827
Nitriles, Isocyanides, and Their Derivatives C-831, C-832, C-833, C-834
Hydroxylamines and Related Compounds C-841, C-842, C-843
Nitroso and Nitro Compounds C-851, C-852
Amine Radical Ions C-861


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