Tungsten(V) bromide
<templatestyles src="Chembox/styles.css"/>
Template:Chembox image cellTemplate:Chembox AllOtherNamesTemplate:Chembox headerbarTemplate:Chembox IndexlistTemplate:Chembox JmolTemplate:Chembox ChEMBLTemplate:Chembox ECHATemplate:Chembox E numberTemplate:Chembox IUPHAR ligandTemplate:Chembox UNIITemplate:Chembox CompToxTemplate:Chembox headerbarTemplate:Chembox HazardsTemplate:Chembox headerbarTemplate:Chembox Datapage checkTemplate:Yesno| Template:Longitem | Template:Unbulleted list |
| ChEBI | Template:Unbulleted list |
| ChemSpider | Template:Unbulleted list |
| DrugBank | Template:Unbulleted list |
| EC Number | Template:Unbulleted list |
| KEGG | Template:Unbulleted list |
| Template:Longitem | Template:Unbulleted list |
| RTECS number | Template:Unbulleted list |
| Script error: No such module "collapsible list". | |
| Script error: No such module "collapsible list". | |
| Template:Longitem | WBr5, Br5W |
| Molar mass | 583.4 g/mol |
| Appearance | brown-black crystals hygroscopic |
| Melting point | Template:Chembox CalcTemperatures |
| Boiling point | Template:Chembox CalcTemperatures |
| Template:Longitem | +250.0·10−6 cm3/mol |
| Template:Longitem | Tungsten(V) chloride |
| Template:Longitem | Molybdenum(V) bromide |
Template:Chembox Footer/tracking container onlyScript error: No such module "TemplatePar".Template:Short description
Tungsten(V) bromide is the inorganic compound with the empirical formula WBr5. The compound consists of bioctahedral structure, with two bridging bromide ligands,[1] so its molecular formula is W2Br10.
Preparation and structure
Tungsten(V) bromide is prepared by treating tungsten powder with bromine in the temperature range 650-1000 °C. The product is often contaminated with tungsten hexabromide.[2]
According to X-ray diffraction, the structure for tungsten pentabromide consists of an edge-shared bioctahedron.[1]
Reactions
Tungsten(V) bromide is the precursor to other tungsten compounds by reduction reactions. For example, tungsten(IV) bromide can be prepared by reduction with aluminium or tungsten.[2] The WBr4 can be purified by chemical vapor transport.
- 3 WBr5 + Al → 3 WBr4 + AlBr3
Excess tungsten pentabromide and aluminum tribromide are then removed by sublimation at 240 °C.
Tungsten(II) bromide can then be obtained heating the tetrabromide.[2] At 450-500 °C, gaseous pentabromide is evolved leaving yellow-green residue of WBr2. An analogous method can also be applied to the synthesis of tungsten(II) chloride.
Reductive substitution reactions
Because it is relatively easy to reduce tungsten pentahalides, they can be used as alternative synthetic routes to tungsten (IV) halide adducts. For example, reaction of WBr5 with pyridine gives WBr4(py)2.[2]
- 2 WBr5 + 7 C5H5N → 2 WBr4(C5H5N)2 + bipyridine + C5H5NHBr
References
<templatestyles src="Reflist/styles.css" />
- ↑ a b Y.-Q. Zheng, K. Peters and H. G. von Schnering (1998) "Crystal structure of tungsten pentabromide, WBr5" Zeitschrift für Kristallographie - New Crystal Structures 213(3) 471
- ↑ a b c d R.E. McCarley, T.M. Brown "The Preparation and Reactions of Some Tungsten (II) and Tungsten (IV) Halides" Inorg. Chem. 1964, volume 3, 1232-1236. Script error: No such module "CS1 identifiers".
Script error: No such module "Check for unknown parameters".