Rhenium(IV) oxide
Rhenium oxide or rhenium dioxide is the inorganic compound with the formula ReO2. This gray to black crystalline solid is a laboratory reagent that can be used as a catalyst. It adopts the rutile structure.
Synthesis and reactions
It forms via comproportionation:Single crystals are obtained by chemical transport, using iodine as the transporting agent.:
At high temperatures it undergoes disproportionation:
It forms rhenates with alkaline hydrogen peroxide and oxidizing acids. In molten sodium hydroxide it forms sodium rhenate: