ESR studies of [RhCl6]4− in various matrices

Abstract

An ESR study of the [RhCl6]4− center in single crystals of AgCl has been made. The g values and chlorine hyperfine interactions observed for the axial chlorines are consistent with a d7 configuration and localization of the odd electron largely in the 4dz2 orbital. The same species has been studied in γ-irradiated single crystals of NaCl doped with [RhCl6]3− and the ESR parameters found were quite similar. Polycrystalline Na3RhCl6⋅12H2O, after γ irradiation at room temperature, appears to give the same species, although only g⊥ can be obtained from the spectrum. Molecular orbital theory has been used to interpret the chlorine hyperfine interactions in terms of bonding parameters for the complex. The delocalization found is smaller than that for [RhBr6]4−.