Magnetic and other studies of ruthenium dioxide and its hydrate

Abstract

The magnetic behaviour of ruthenium dioxide up to 1000°K is interpreted in terms of J being ca.– 3000 cm.^–1 in dioxo-bridged chains of ruthenium atoms. The high electrical conductivity as well as certain structural features imply that the average oxidation state of the ruthenium atoms is substantially greater than +4.

The oxide hydrate has a high surface area; it is formulated as RuO_{2 +x}, yH₂O since there can be an excess (chemisorbed) of oxygen particularly after removal of some of the water. Values of x up to 0·12 have been found whereas y is often 1 to 1·3. The susceptibility, though generally similar to that of RuO₂, varies from sample to sample: its behaviour is discussed in relation both to the influence of adsorbed groups and also to some terminal ruthenium atoms behaving as mononuclear Ru(V), i.e., being in the d³ state. Expected spectral bands in the infrared have not been detected owing to the presence of electronic conductance bands.