Improved Access to Organo‐Soluble Di‐ and Tetrafluoridochlorate(I)/(III) Salts

Abstract A facile one‐pot gram‐scale synthesis of tetraalkylammonium tetrafluoridochlorate(III) [cat][ClF 4 ] ([cat]=[NEt 3 Me] + , [NEt 4 ] + ) is described. An acetonitrile solution of the corresponding alkylammonium chloride salt is fluorinated with diluted fluorine at low temperatures. The reaction proceeds via the [ClF 2 ] − anion which is structurally characterized for the first time. The potential application of [ClF 4 ] − salts as fluorinating agents is evaluated by the reaction with diphenyl disulfide, Ph 2 S 2 , to pentafluorosulfanyl benzene, PhSF 5 . The CN moieties in acetonitrile and [B(CN) 4 ] − are transferred in CF 3 groups. Exposure of carbon monoxide, CO, leads to the formation of carbonyl fluoride, COF 2 , and elemental gold is dissolved under the formation of tetrafluoridoaurate [AuF 4 ] − .