Effect of Ionising Radiation on Potassium Pentacyanonitrosylruthenate(II): An Electron Spin Resonance Study

Abstract

Amorphous potassium pentacyanonitrosylruthenate (II) was synthesized and characterized by UV, IR, X-ray diffraction and thermogravimetric analysis. Electron Spin Resonance spectroscopy reveals the presence of paramagnetic ruthenate (I) complexes and NO2 radicals in the X-irradiated diamagnetic salt. Spin-hamiltonian parameters of the [Ru(CN)5NO]3- complex (g⊥= 2.0064, A⊥. (14N) = 60.7 MHz, g∥ = 1.999, A∥ (14N) = 77.3 MHz) support an electron capture in a π* molecularorbital of the nitrosyl group mixed with dxz and dyz ruthenium orbitals as recently predicted by theoretical calculations. Silver ions, present as impurities, are reduced to Ag(0) by X-irradiation and coordinate to four magnetically equivalent nitrogens in a distorted site, giving rise to a well resolved anisotropic ESR powder spectrum.