Quaternary Salts Containing the Pentafluorosulfanyl (SF5) Group

The first quaternary salts of pyridine (2), N-methyl imidazole (3), N-propyl triazole (4), and pyridazine (5) that contain the pentafluorosulfanyl (SF5) group were prepared and characterized. Neat reactions of the aromatic nitrogen compounds with SF5(CF2)n(CH2)mI (n = 2 or 4, m = 2 or 4) gave quaternary iodides 6a-c, 7a-c, 8a, and 9a,b, which were metathesized with LiN(SO2CF3)2 to form the bis(trifluoromethylsulfonyl)amides 10a-c, 11a-c, 12a, and 13a,b, in high yields. With the exception of the pyridine bis(trifluoromethylsulfonyl)amide salts, the compounds melted or exhibited a Tg at <0 C. The methylimidazolium, pyridinium, and pyridazinium salts exhibited densities of ~2 g/cm^3. Particularly striking was the density of CF3(CF2)5 (CH2)2-pyridazinium N(CF3SO2)2 measured at 2.13 g/cm^3; however, an atypically high density for the 1-CF3(CF2)5(CH2)2-3-methyl imidazolium amide (14) was also observed at 1.77 g/cm^3. All quaternary salts were characterized via IR, 19F, 1H, and 13C NMR spectra and elemental analyses.