Super-superhyperfine interactions in irradiated sodium chloride single crystals doped with Co(III), Rh(III) and Ir(III) hexacyanides and hexachlorides: an EPR study

Abstract

The EPR spectra of the paramagnetic complexes M(CN)4Cl2:NaCl obtained by X-ray irradiation on trivalent Co, Rh, and Ir hexacyanides inserted in NaCl, as well as RhCl64- and IrCl64- complexes in NaCl, present an additional hyperfine structure besides the well known two-chlorine first-ligands one. This structure is proved to arise from the interaction between the unpaired electron and the nearest-neighbour sodium atoms. The observation of this structure in sodium chloride and not in the analogous potassium chloride host lattice is explained by overlap and covalent effects in a molecular orbital approach.