Ruthenium Sesquioxide, Ru₂O₃

When strongly heated in air ruthenium yields a bluish black Ruthenium Sesquioxide, Ru₂O₃ which is not reduced at white heat. Claus believed that the sesquioxide, Ru₂O₃, could be produced in this way, but Gutbier and Ransohoff have adduced evidence in favour of the assumption that the product is not a well-defined oxide, but an intimate mixture of ruthenium and its dioxide, RuO₂. No other method tried by the last-named authors yielded the sesquioxide in the anhydrous condition, although decomposition of the corresponding hydroxide, Ru₂(OH)₆, by ignition in a current of carbon dioxide gave indications that the oxide is capable of existence.