An electron spin resonance study of the bonding in potassium hexanitratoiridate(IV)

Abstract

Electron spin resonance measurements on K₂[lr(NO₃)₆] have yielded the following parameters: g=–1.12, A(¹⁹³lr)= 221 × 10^–4 cm^–1, A(¹⁹¹Ir)= 180 ± 10^–4 cm^–1, f_π= 0.38. There is considerable delocalisation of the metal d-electrons into π* orbitals on the nitrate group, being up to three times that found for the corresponding halogen complexes. A qualitative molecular-orbital bonding scheme is presented which describes the bonding between the metal and the bidentate nitrate ligands.