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

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)](−).