Rhenium trioxide chloride

Rhenium trioxide chloride is an inorganic compound with the formula ReO3Cl. It is a colorless, distillable, diamagnetic liquid. It is a rhenium oxychloride. The material is used as a reagent in the preparation of rhenium compounds.

Synthesis and reactions
Rhenium trioxide chloride can be prepared by chlorination of rhenium trioxide:
 * 2 ReO3 + Cl2 ->  2 ReO3Cl

With Lewis bases (L), rhenium trioxide chloride reacts to form adducts with the formula ReO3ClL2.

The compound hydrolyzes readily to give perrhenic acid.

Structure
The compound adopts a tetrahedral structure with Re-O and Re-Cl bond distances of 1.71 and 2.22 Å. In contrast rhenium trioxide fluoride (ReO3F) is polymeric with octahedral Re centers.