Lithium - Heavier alkali metal exchange in organolithium compounds induced by alkoxides of heavier alkali metals and reactions occurring in this system
Organolithium compounds of various types undergo an exchange reaction lithium-heavier alkali metal when treated with heavier alkali metal alkoxides. In the presence of a third reactive compound the exchange reaction gives rise to a compound of the third component substituted with the heavier alkali metal. Using this exchange reaction, organic derivatives of heavier alkali metals in the individual state can be easily prepared. The mechanism of such reactions is discussed, and the formation of lithium alkoxide is assumed to contribute significantly to the driving force of the reaction. Organic compounds of heavier alkali metals possess a considerably higher reactivity than organolithium compounds, and are therefore used as reactive intermediates in preparative chemistry, or as polymerization initiators in macromolecular chemistry. This review provides information about the scope and possibilities of this exchange reaction, which has been increasingly widely used in the recent years.
Analytical derivatives of the individual state energies in ensemble density functional theory method. I. General formalism