EPR of Electron Irradiated K sub 4 Os Sup(II) (CN) Sub 6 in KCl Single Crystals

摘要

Electron irradiation of diamagnetic Os(CN) sub 64- ion in a KCl host lattice at 77 exp 0 K produces three paramagnetic species. Annealling experiments reveal that these species decay among themselves and among four other species. EPR studies indicate that each species can be assigned to a pentacoordinated Os sup(I) (CN) sub 5 complex, with 5d exp 7 low spin configuration arising from the trapping of an electron in a d sub(z) sup(2) orbital, associated with a charge compensating vacancy located at different lattice sites. The EPR spectra show evidence of strong quadrupolar interaction. The g values, the magnetic hyperfine interaction and a minimum value for the quadrupolar interaction with the exp 189 Os nucleus are presented and discussed. Ligand hyperfine structure with four equivalent and one non-equivalent nitrogens is measured and the ligand f sub(s) and f sub(p) spin densities are calculated and discussed. The relative contribution of 5d and 6p electrons to the electric field gradient is discussed and compared with Moessbauer spectroscopy results. (Atomindex citation 09:364143)