Editing Group 7 element (section)

==== Rhenium ====

The most common rhenium chlorides are [[Rhenium hexachloride|ReCl<sub>6</sub>]], [[Rhenium pentachloride|ReCl<sub>5</sub>]], [[Rhenium tetrachloride|ReCl<sub>4</sub>]], and [[Rhenium trichloride|ReCl<sub>3</sub>]].<ref name="G&W">{{Greenwood&Earnshaw2nd}}</ref> The structures of these compounds often feature extensive Re-Re bonding, which is characteristic of this metal in oxidation states lower than VII. Salts of [Re<sub>2</sub>Cl<sub>8</sub>]<sup>2−</sup> feature a [[quadruple bond|quadruple]] metal-metal bond. Although the highest rhenium chloride features Re(VI), fluorine gives the d<sup>0</sup> Re(VII) derivative [[rhenium heptafluoride]]. Bromides and iodides of rhenium are also well known.

Like tungsten and molybdenum, with which it shares chemical similarities, rhenium forms a variety of [[Oxohalide|oxyhalides]]. The oxychlorides are most common, and include ReOCl<sub>4</sub>, ReOCl<sub>3</sub>.