Two elusive but relatively simple SF5 compounds have been independently prepared by two research groups : SF5CN results from treatment of dirhodane with fluorine [Eq. (a)], and the structural isomer SF5NC can be obtained by debromination of SF5N = CBr2 [Eq. (b)]. The IR spectrum of the cyanide displays the characteristic CH stretching band at 2235 cm−1, while the corresponding band for the isocyanide is located at 2080 cm−1. Even though SF5NC isomerizes to SF5CN at room temperature and pressures < 50 Torr, the cyanide itself is remarkably stable. Both are gaseous, and they are expected to display unusual chemical and physical properties.