Rhenium pentachloride
Encyclopedia
Rhenium pentachloride is an inorganic compound
of chlorine
and rhenium
. The compound has the formula Re2Cl10 but it is usually referred to as the pentachloride. It is a red-brown solid. It is the highest chloride of rhenium.
This compound was first prepared in 1933, a few years after the discovery of rhenium. The preparation involves chlorination
of rhenium at temperatures up to 900 °C. The material can be purified by sublimation.
Being formed by burning Re metal in chlorine, ReCl5 is the most oxidized binary chloride of Re. With a d2 configuration, ReCl5 could conceivably be further chlorinated. Rhenium hexachloride (ReCl6) is uncertain, but rhenium hexafluoride and heptafluorides are known.
Although rhenium pentachloride has no commercial applications, it is of historic significance as one of the early catalysts for olefin metathesis
. Reduction gives rhenium trichloride
.
Oxygenation affords the Re(VII) oxychloride:
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...
of chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
and rhenium
Rhenium
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an average concentration of 1 part per billion , rhenium is one of the rarest elements in the Earth's crust. The free element has...
. The compound has the formula Re2Cl10 but it is usually referred to as the pentachloride. It is a red-brown solid. It is the highest chloride of rhenium.
Structure and preparation
Rhenium pentachloride has a bioctahedral structure and can be formulated as Cl4Re(μ-Cl)2ReCl4. The Re-Re distance is 3.74 Å. The motif is similar to that seen for tantalum pentachloride.This compound was first prepared in 1933, a few years after the discovery of rhenium. The preparation involves chlorination
Chlorination
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water...
of rhenium at temperatures up to 900 °C. The material can be purified by sublimation.
Being formed by burning Re metal in chlorine, ReCl5 is the most oxidized binary chloride of Re. With a d2 configuration, ReCl5 could conceivably be further chlorinated. Rhenium hexachloride (ReCl6) is uncertain, but rhenium hexafluoride and heptafluorides are known.
Uses and reactions
It degrades in air to a brown liquid.Although rhenium pentachloride has no commercial applications, it is of historic significance as one of the early catalysts for olefin metathesis
Olefin metathesis
Olefin metathesis or transalkylidenation is an organic reaction that entails redistribution of alkylene fragments by the scission of carbon - carbon double bonds in olefins . Its advantages include the creation of fewer sideproducts and hazardous wastes. Yves Chauvin, Robert H. Grubbs, and Richard R...
. Reduction gives rhenium trichloride
Rhenium trichloride
Rhenium trichloride is a compound of rhenium and chlorine. It was first discovered in 1932 by Geilnann, Wriuce, and Biltz.-Structure and physical properties:...
.
Oxygenation affords the Re(VII) oxychloride:
- ReCl5 + 3 Cl2O → ReO3Cl + 5 Cl2