Alkylammonium chloride, molten

Excision reactions are sometimes accompanied by redox chemistry. For example, dissolution of the 2D solid Na4Zr6BeCli6 in acetonitrile in the presence of an alkylammonium chloride salt results in simultaneous reduction of the cluster cores (144). Here, the oxidation product remains unidentified, but is presumably the solvent itself. As a means of preventing such redox activity, Hughbanks (6) developed the use of some room temperature molten salts as excision media, specifically with application to centered zirconium-halide cluster phases. A number of these solids have been shown to dissolve in l-ethyl-2-methylimidazolium chloride-aluminum chloride ionic liquids, providing an efficient route to molecular clusters with a full compliments of terminal chloride ligands. Such molten salts are also well suited for electrochemical studies. 

Not much work has been reported on electrochemical studies in molten organic compounds as yet. One example of an organic melt is a molten alkylammonium chloride. Kisza " reported the electromotive series of several couples in molten dimethylammonium chloride. The same... 

The alkylammonium nitrate salts and salts containing the l-alkyl-2-alkylimidazolium cation with chloride or bromide anions were mostly molten salts, in that their melting points were >100 °C. In contrast, the PILs that contained alkylammonium cations with small carboxylic acids and most of the salts with an imidazolium cation were predominately RT-PILs, or had low melting points. 

The history of ionic liquids (and the closely related molten salts) has a rather ill-defined beginning, although it is most commonly dated back to 1914 and the work of Walden on the use of alkylammonium nitrates. - The next burst of interest occurred with the discovery of chloroaluminates formed by combining quaternary heterocyclic cations with aluminum chloride. These materials exhibited a great deal of potential for use in a variety of areas, but all suffered from extreme sensitivity to moisture. 

About the earliest study of molten organic salts was the measurement of surface tensions by Walden of a number of alkylammonium nitrates, thiocyanates, and halides. Most recently the chlorides have been studied by Kisza and Hawranek. The surface tensions of these salts are similar to those for organic liquids and they range from 20 to 50 dyn/cm. These... 

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See also in sourсe #XX -- [ , ]

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