Bromopentacarbonylrhenium(I) is an

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemi ...

of rhenium, commonly used for the syntheses of other rhenium complexes.

Preparation

Bromopentacarbonylrhenium(I) is commercially available. It is also easily and inexpensively synthesized by the oxidation of dirhenium decacarbonyl with

bromine Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table (halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a simil ...

: :Re₂(CO)₁₀ + Br₂ → 2 ReBr(CO)₅ It was first prepared by the "reductive carbonylation" of rhenium(III) bromide: :ReBr₃ + 2 Cu + 5 CO → BrRe(CO)₅ + 2 CuBr Copper(I) bromide is a byproduct.

Reactions

Bromopentacarbonylrhenium(I) is a precursor to other rhenium complexes. It reacts with

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic t ...

and

acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main componen ...

to give pentacarbonylhydridorhenium (HRe(CO)₅). : Re(CO)₅Br + Zn + HO₂CCH₃ → ReH(CO)₅ + ZnBrO₂CCH₃ It also reacts with

tetraethylammonium bromide Tetraethylammonium bromide (TEAB) is a quaternary ammonium compound with the chemical formula C8H20N+Br−, often written as "Et4N+Br−" in the chemical literature. It has been used as the source of tetraethylammonium ions in pharmacological and ...

diglyme Diglyme, or bis(2-methoxyethyl) ether, is a solvent with a high boiling point. It is an organic compound which is the dimethyl ether of diethylene glycol. (The name ''diglyme'' is a portmanteau of ''diglycol methyl ether''.) It is a colorless liq ...

to give Et₄sub>2 eBr₃(CO)₃) an important precursor to compounds containing the rhenium tricarbonyl fragment. Heating bromopentacarbonylrhenium(I) in water give the tri aquo complex: :ReBr(CO)₅ + 3 H₂O → e(H₂O)₃(CO)₃r + 2 CO This route avoids the formation of the tetraethylammonium bromide byproduct, which is often difficult to remove from reaction mixtures.

References

{{Rhenium compounds Organorhenium compounds Carbonyl complexes Bromo complexes