Ammonium compounds, nomenclature

Hofmann elimination, quaternary ammonium compounds, 2 737 Hofmann-Gerhardt nomenclature,... 

Quaternary ammonium salt (QAS), 9 676 salicylic acid and, 22 11 Quaternary bismuth compounds, 4 33-34 Quaternary compounds, nomenclature for, 77 390-391... 

Nomenclature.—A definite system of nomenclature has been adopted for metal-ammines, and the old names derived from the colour of the compounds have, in the main, been abandoned, as they lead to confusion. The system adopted is that suggested by Werner. Ammonia molecules present in the complex are indicated by the terms monam-mino, diammino, triammino, tetrammino, pentammino, hexammino, the word ammino, written with a double m, having been adopted to show the relationship with ammonia and to distinguish from the ammonium salts and the substituted ammonia compounds, namely, the amines. 

The acidic character of hexyl is one of its most important features. It was first observed by Aleksandrov [24] when preparing ammonium salt of hexyl. Later this property was investigated by Hantzsch and Opolski [25], who obtained the O-methyl ether of the aci-form of hexyl, according to Hantzsch s nomenclature (la). The aci-form of the compound can yield salts and O-ethers (esters). It is intensely coloured due to the presence of the quinonoid ring. 

Most of the material in Rouelle s memoirs was well known to German chemists but their publication was probably useful in instructing the members of the Paris Academy. Double salts seem to have been first recognised by Fourcroy (1790) in the case of magnesium ammonium sulphate he calls them triple salts , the double salts (as in the old nomenclature) being compounds of an acid and a base. 

This distinction between the two types of carbocations was championed by Olah, and is consistent with other nomenclature. Just as hydronium and ammonium ions represent pro-tonated forms of water and ammonia, carbonium ions can be considered to contain proton-ated forms of methane and other typical, tetravalent carbon compounds. Likewise, carbe-niumions can be thought of as protonated carbenes ( CH2 + givesCHs ), consistent with... 

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