Synthesis and structure of novel perfluorinated iodinanes

Several novel iodinanes have been prepared and structurally characterized. The structures of all are heavily influenced by secondary bonding involving the iodine(III) center and oxygen or chlorine. The iodonium salt, [Ph(CF3CH2)I]CF3SO2NSO2CF3, has a chain structure with the anion in a transoid conformation, while the diphenyl derivative, [Ph2I]CF3SO2NSO2CF3, forms a dimeric structure which stabilizes a cisoid conformation of the anion. In comparison to the known compound, PhICl2, which has a simple chain structure, perfluoroalkyliodinedichlorides CF3CH2ICl2 and CHF2(CF2)5CH2ICl2, have more complicated structures in which weak interactions between chains, coupled with aggregation of perfluoro groups, results in the formation of layers. The dicarboxylate, CF3CH2I(O2CCF3)2 has a T-shaped coordination similar to other derivatives, but forms a tetrameric array of molecules not previously seen.