In the OSF(4)/Me(2)NSiMe(3) system besides the long known Me(2)NS(O)F(3) only the trisubstituted derivative is isolated as (Me(2)N)(3)SO(+)Me(3)SiF(2)(-) (3). Similar to (Me(2)N)(3)S(+)Me(3)SiF(2)(-) compound 3 is an excellent fluoride ion donor. With AsF(5) and HF the corresponding hexafluoroarsenate (Me(2)N)(3)SO(+)AsF(6)(-) (4) and the hydrogen bifluoride (Me(2)N)(3)SO(+)HF(2)(-) (5) are formed in almost quantitative yield. X-ray structure determinations of 3-5 surprisingly showed two different types of structures for the cation. In 3 and 5 this cation has C(3) symmetry, while in the hexafluoroarsenate 4 a (Me(2)N)(3)S(+)-like structure with C(s)() symmetry is determined. The experimental results for (Me(2)N)(3)SO(+) and (Me(2)N)(3)S(+) are compared with theoretical calculations for these cations and their isoelectronic neutral counterparts, the phosphorus amides (Me(2)N)(3)PO and (Me(2)N)(3)P, respectively.

The syntheses of Az2S(O)F2 (AZ=pyrazole (7d), imidazole (7e), 1,2,4-triazole (7f) from OSF4 and the corresponding trimethylsilylazoles AzSiMe3 and the structures of 7d and f as well as those of [C6H5(CH3)N]2SF2 (3b) and CF3S(azole)SF2 (AZ=1,2,4-triazole) (3f) are reported, the structure of [(CH3)2N]2SF2 (3a) was re-determined at −100°C. The steric influence of the different substituents (F, CF3, NR2, azolide), of the oxidation state and of the lone pair (LP) in comparison with the doubly bonded oxygen is discussed.

Bis(imidazole)sulfur difluoride (4), bis(pyrazole)sulfur difluoride (6), and bis(1,2,4-triazole)sulfur difluoride (8) are formed in the reactions of N-(trimethylsilyl)imidazole, N-(trimethylsilyl)pyrazole, and 1-(trimethylsilyl)-1,2,4-triazole with SF(4), in high yield. The ring systems in these three molecules occupy equatorial positions in the pseudo-trigonal-bipyramidal coordination sphere of the central sulfur atoms. The angles between the planes of the ring substituents and the FSF axis for 4 and 6 are in the range 23.6-35.3 degrees, and in 8 the triazole rings are almost parallel (deviation 1.7 degrees ). The interaction between the heterocyclic substituents and the sulfur centers and their influence on the axial and equatorial bonds is discussed.

From CF3SF3 and the silylated azoles N-trimethylsilylpyrazole, N-trimethylsilylimidazole, and 1-trimethylsil-1,2,4-triazole the corresponding azole trifluoromethyl sulfurdifluorides Az-SF2-CF3 were prepared in 30-40% yield (Az = pyrazole, imidazole, 1,2,4-triazole). The X-ray structure of the pyrazole derivative was determined.

Durch Umsetzung von CF3SF3 mit den silylierten Azolen N-Trimethylsilylpyrazol, N-Trimethylsilylimidazol und 1-Trimethylsilyl-1,2,4-Triazol wurden die entsprechenden Azoltrifluormethylschwefeldifluoride Az–SF2–CF3 in 30–40%iger Ausbeute dargestellt (Az = Pyrazol, Imidazol, 1,2,4-Triazol). Die Struktur des Pyrazolderivats wurde durch Röntgenbeugung bestimmt. Azoltrifluoromethylsulfurdifluorides From CF3SF3 and the silylated azoles N-trimethylsilylpyrazole, N-trimethylsilylimidazole, and 1-trimethylsilyl-1,2,4-triazole the corresponding azole trifluoromethyl sulfurdifluorides Az–SF2–CF3 were prepared in 30–40% yield (Az = pyrazole, imidazole, 1,2,4-triazole). The X-ray structure of the pyrazole derivative was determined.

The breakdown of the polymeric structure of alkali metal cyclopentadienides can be achieved by (Me2N)3S+ Cp− [(TAS)Cp]. This leads to the salts TAS+[Cp2M]− (MLi, Na, K). On the other hand, [TAS2Cp]+[Cp2M]− salts are obtained if this reaction is carried out in the molar ratio 2:1, the structure analysis of the Na compound shows that sandwich and inverse sandwich units are present side by side.

By conversion of the sulfonium salt 1 with the cyclopentadiene 2 the readily soluble salt 3 is obtained in high yield. “Naked” Cp− ions and cations of [{(Me2N)3S}2Cp]+ with an inverse sandwich structure are present in crystals of 3. A variety of silylated N-heterocycles react with 1 in a similar way to form the corresponding salts. These salts are interesting inter alia for their potential use as building blocks in synthesis.