The electrochemical deposition of magnesium was investigated in the ionic liquids 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIm BF4 ), 1-butyl-1-methylpyrrolidinium triflate (BMP TfO), and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfo nyl)amide (BMP Tf2N ). The electrochemical window of the imidazolium ionic liquid was insufficient for reduction of magnesium triflate, whereas the BMP systems can be used for the reduction of several magnesium salts. Studies of the reduction of other magnesium salts were carried out in nonaqueous solvents such as propylene carbonate for comparison with the work in ionic liquids. Stripping peaks for magnesium were observed in solutions of phenylmagnesium chloride in BMP Tf2N at elevated temperatures (150°C) .

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The electrochemical and spectroscopic properties of 9,10‐anthraquinone (AQ) in the low temperature AlCl3 :n‐butylpyridinium chloride (BuPyCl) molten salt system have been studied as a function of melt acidity. Infrared spectroscopic data indicate that AQ exists in the uncomplexed state in the basic melt ( 0.8 AlCl3 :1.0 BuPyCl). The electrochemical behavior in this region involves a single‐process two‐electron reduction (with slow electron transfer) of AQ to its dianion, the reduction mechanism probably proceeding by an ECE pathway. Oxidation of the dianion back to AQ occurs at a potential considerably positive (600 mV) of the potential for AQ reduction, thus indicating some interaction of the dianion with the melt. The complexation of AQ by Al2Cl7− in the acidic melt ( 1.2 AlCl3 :1.0 BuPyCl) produces AQfalse(AlCl3)2 as indicated both by infrared spectroscopy and chemical analysis. This complexation results in a shift in potential for the reduction process compared to the corresponding potential for AQ reduction in the basic melt of +1.4V. The reduction of AQfalse(AlCl3)2 also involves a single‐wave two‐electron process (with faster electron transfer than in the basic melt), thought to proceed by a disproportionation mechanism. Since the same separation in potentials for AQfalse(AlCl3)2 reduction and subsequent oxidation in the acidic melt was observed as that seen for AQ in the basic melt, some interaction of the dianion with the acidic melt is also evident. As the composition of the melt was varied through the neutral region (approx. 1.0 AlCl3 :1.0 BuPyCl), in which the acidity is changing rapidly, an additional process due to reduction of AQfalse(AlCl3false) was observed; by adjustment of melt acidity by small additions of AlCl3 or BuPyCl, a melt containing all three species AQ, AQfalse(AlCl3false) , and AQfalse(AlCl3)2 could be obtained. Electrochemical studies of this system indicated that interconversion among the various species upon reduction is rather slow, an observation reflecting the low levels of Al2Cl7− present as well as the unbuffered nature of the melt in this region.

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