Esr study of irradiated pentacyanonitrosyl cobaltate (ii)

An ESR study of ϒ-irradiated pentacyanonitrosyl cobaltate (II) shows the presence of two paramagnetic species. One, with [formula omitted] and much lower 59 Co hyperfine interactions. The ESR parameters are shown to be consistent with those predicted for the species [Co(CN)5 NO] 4- with Cs symmetry, a bent Co-N-O bond, and ad7 configuration with the odd electron in an a’ orbital formed by mixing the cobalt dx2-y2 and dz2 orbitals. Theoretical arguments are advanced to show that, in general, small metal hyperfine splittings in low symmetry ions do not necessarily establish that the unpaired electron is in a ligand-dominated orbital. © 1974, Taylor & Francis Group, LLC. All rights reserved.