First X-ray structure of hexaamminecobalt(III) salt with complex fluoroanion: Synthesis and characterization of [Co(NH3)6]X·SiF6·nH2O, where X = Cl, Br, I and NO3 and crystal structure of [Co(NH3)6]Cl·SiF6·2H2O

In the newly synthesized salts, [Co(NH3)6]X·SiF6·nH2O where X = Cl, Br, I, and NO3, the lowering of SiF stretching frequency in SiF62− is due to hydrogen bonding interactions. This is consistent with single crystal X-ray structure determination.