Macrocyclic chemistry in reducing environments: From concentrated metal solutions to crystalline electrides

Abstract

Macrocvclic and macrobicyclic complexants for the alkali metal cations can be used to greatly enhance alkali metal solubilities in a variety of amine and ether solvents. This provides concentrated solutions that contain alkali metal anions and/or solvated electrons which should be useful in organic and inorganic synthesis. The solvent dimethyl ether and fully methylated macrocyclic aza-analogs of crown ethers provide exceptionally stable solutions. Crystalline alkalides and electrides can be prepared by slow cooling or dimethyl ether evaporation from dimethyl ether-trimethylamine mixtures. The crystal structures of 12 alkalides and two electrides have been determined and are correlated with such measurements as optical spectra, powder conductivities, magnetic susceptibilities and alkali metal NMR spectra. The factors that determine stabilities of solutions and solid alkalides and electrides are discussed. © 1989 IUPAC