A new route to the syntheses of alkali metal bis(fluorosulfuryl)imides: Crystal structure of LiN(SO2F)2

A new route for the preparation of Li and Na salts of imido-bis(sulfuric acid) difluoride from KN(SO2F)2 as a starting material is described. KN(SO2F)2 was converted to Li and Na salts by metathetical reactions with lithium and sodium perchlorates in acetonitrile, while Rb and Cs salts were obtained from imido-bis(sulfuric acid) difluoride liberated from its K-salt. The crystal structure of lithium bis(fluorosulfuryl) imide LiN(SO2F)2 (LISFI) was determined.