The Frontier in Ionics Nonaqueous Solutions

Studies of ionic solutions have been overwhelmingly aqueous in the hundred years or so in which they have been pursued. This has been a blessing, for water has a dielectric constant, s, of 80, about ten times larger than the range for most nonaqueous solvents. Hence, because the force between ions is proportional to 1/e, the tendency of ions in aqueous solutions to attract each other and form groups is relatively small, and structure in aqueous solutions is therefore on the simple side. This enabled a start to be made on the theory of ion-ion attraction in solutions. 

Electrochemical measurements (mainly conductances) have been made in both the organic and the pure electrolyte kind of nonaqueous solution for at least two generations. Why, then, is there talk of nonaqueous electrochemistry as one of the frontiers of the field  

One reason is that much better methods of detecting impurities (parts per billion) now exist and hence of purifying solvents (and keeping them pure—they all tend to pick up water). However, there is a greater reason and that is the emergence of several new methods for determining structure. These are 

X-ray diffraction measurements in solution (a development of the earliest method of structural determination) 

X-ray absorption measurements of fine stmcture in solution (EXAFS) 

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