Electron Paramagnetic Resonance of Electron Irradiated K3Rh(CN)6 in a KCl Lattice

Abstract

Electron irradiation of the diamagnetic Rh(CN)63− ion in a KCl host lattice produces three paramagnetic species. EPR studies reveal that one of the species can be assigned as Rh(CN)4Cl24−, of D4h symmetry, 4d7 low spin configuration, arising from the trapping of an electron in a dz2 orbital followed by the substitution of two axial cyanides by chloride ions. The experimental data have been interpreted in terms of a spin Hamiltonian yielding the principal values of the g and hyperfine tensors as g‖ = 1.995, g⊥ = 2.297, A‖Rh = − 40.8 × 10−4cm−1, A⊥Rh = − 36.9 × 10−4cm−1, A‖Cl = + 27.8 × 10−4cm−1, A⊥Cl = + 12.4 × 10−4cm−1. Theoretical estimates of g values confirm this assignment. A semiempirical estimate of the unpaired electron density on the metal and ligands is presented.