Structural and spectral studies of hydrated hexaamminecobalt(III)–hexafluororhenate(IV)

The crystal structure of the [Co(NH3)6]2[ReF6]3·3H2O (I) salt is reported. The salt crystallizes in the trigonal space group P31m with the following unit cell dimensions: a = 15.8714(4) A, b = 15.8714(4) A, and c = 9.8657(4) A. The structure of (I) consists of [Co(NH3)6]3+ cations, [ReF6]2− anions, and co-crystallized water molecules which are linked by hydrogen bonding. In (I), independent [ReF6]2− anions and [Co(NH3)6]3+ cations octahedron are slightly distorted. Characteristic vibration bands of the [Co(NH3)6]3+ cation, [ReF6]2− anion as well as the co-crystallized H2O molecules are observed in the infrared spectra of (I). UV-Visible analyses in water showed that the absorption of the [Co(NH3)6]3+ cation predominate the spectra of (I).