Bromopentacarbonylrhenium(I)
Chemical compound
From Wikipedia, the free encyclopedia
Bromopentacarbonylrhenium(I) is an inorganic compound of rhenium, commonly used for the syntheses of other rhenium complexes.
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| Names | |
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| IUPAC name
Bromidopentacarbonylrhenium | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.034.607 |
| EC Number |
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PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| Re(CO)5Br | |
| Molar mass | 406.16 g/mol |
| Appearance | colorless |
| Melting point | sublimes 85-90 °C (0.2 mm Hg) |
| Solubility in chlorocarbons | soluble |
| Hazards | |
| GHS labelling: | |
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| Danger | |
| H301, H311, H315, H319, H331, H335 | |
| P261, P264, P270, P271, P280, P301+P310, P302+P352, P304+P340, P305+P351+P338, P311, P312, P321, P322, P330, P332+P313, P337+P313, P361, P362, P363, P403+P233, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation
Bromopentacarbonylrhenium(I) is commercially available. It is also easily and inexpensively synthesized by the oxidation of dirhenium decacarbonyl with bromine:[1]
- Re2(CO)10 + Br2 → 2 ReBr(CO)5
It was first prepared by the "reductive carbonylation" of rhenium(III) bromide:[2]
- 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 and acetic acid to give pentacarbonylhydridorhenium (HRe(CO)5).[3]
- Re(CO)5Br + Zn + HO2CCH3 → ReH(CO)5 + ZnBrO2CCH3
It also reacts with tetraethylammonium bromide in diglyme to give [NEt4]2[ReBr3(CO)3)], an important precursor to compounds containing the rhenium tricarbonyl fragment.[4]
Heating bromopentacarbonylrhenium(I) in water give the triaquo complex:
- ReBr(CO)5 + 3 H2O → [Re(H2O)3(CO)3]Br + 2 CO
This route avoids the formation of the tetraethylammonium bromide byproduct, which is often difficult to remove from reaction mixtures.[5]