Solvent-free anhydrous Li+, Na+ and K+ salts of [B(3,5-(CF3)2C6H3)4]-, [BArF4]-. Improved synthesis and solid-state structures

A modified, convenient, preparation of solvent-free, anhydrous, Li+, Na+ and K+ salts of the ubiquitous [BAr4F](-) anion is reported, that involves a simple additional recrystallisation step. Anhydrous Na[BAr4F], K[BAr4F], and [Li(H2O)][BAr4F], were characterised by single-crystal X-ray diffraction.