Chemical Properties
-100mesh with 99.95% purity; red cub crystal(s); green luster imparted by transmitted light; disproportionates in vacuum to Re2O7 and ReO2 [MER06] [CER91]
Uses
Rhenium(VI) oxide is involved as a catalyst for the hydrogenation of carboxylic acids and carboxamides. It is involved in the alkene epoxidation reactions.
Synthesis
Rhenium trioxide can not be prepared directly from the elements, can be produced by CO at 300 reduction of dirhenium heptaoxide:
Re2O7 + CO 2 ReO3 + CO2
Toxics Screening Level
The ITSL for rhenium oxide is 0.1 μg/m3 based on an annual averaging time.