Rhenium(IV) oxide explained

Rhenium(IV) 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:^[1]

2 Re₂O₇ + 3 Re → 7 ReO₂Single crystals are obtained by chemical transport, using iodine as the transporting agent.:^[2]

ReO₂ + I₂ ReO₂I₂

At high temperatures it undergoes disproportionation:

7ReO₂ → 2Re₂O₇ + 3Re

It forms rhenates with alkaline hydrogen peroxide and oxidizing acids.^[3] In molten sodium hydroxide it forms sodium rhenate:^[4]

2NaOH + ReO₂ → Na₂ReO₃ + H₂O

Notes and References

1. G. Glemser "Rhenium (IV) Oxide" Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1480.
2. Book: Rogers . D. B. . Butler . S. R. . Shannon . R. D. . 1972 . Single Crystals of Transition-Metal Dioxides . Single Crystals of Transition‐Metal Dioxides . Inorganic Syntheses . XIII . 135–145 . 10.1002/9780470132449.ch27 . 9780470131725 .
3. Web site: RHENIUM DIOXIDE - Manufacturer . Aaamolybdenum.com . 2012-08-06 . dead . https://web.archive.org/web/20030209232809/http://www.aaamolybdenum.com/RheniumDioxide.html . 2003-02-09 .
4. G. Glemser "Sodium Rhenate (IV)" Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1483.