Tungsten hexachloride

Tungsten hexachloride and molybdenum pentafluoride desulfurize 2-methylthiirane to propene (72DOK(207)899) and a ruthenium(II) complex desulfurizes thiirane (73JA4758). 

It is dangerous to attempt the preparation from tungsten hexachloride, aluminium powder and carbon monoxide in an autoclave of greater than 0.3 1 capacity. 

Explosions sometimes resulted on opening sealed tubes in which complex mixed chloride salts of this compound had been prepared. There is no obvious source of pressure in the reaction mixture of tungsten hexachloride, sodium and aluminium chlorides and aluminium metal. 

See Molybdenum pentachloride Sodium, or Sodium sulfide See Tungsten hexachloride Sodium sulfide... 

Tungsten hexabromide, 25 379 Tungsten hexacarbonyl, 25 377 Tungsten hexachloride, 25 378 uses for, 25 387... 

Tungsten hexacarbonyl is produced by heating tungsten metal with carbon monoxide at high pressure. Also, carbonyl can be prepared by reducing the tungsten hexachloride by heating with iron powder under carbon monoxide pressure. 

To an oven-dried 250-mL Schlenk flask under argon and equipped with a magnetic stirbar are added 0.5 g of granular dri-Na [Baker, 10% sodium and 90% lead as alloy] and, via syringe, methoxytrimethylsilane (30 mL, 22.6 g, 0.217 mol, 3.03 equiv). Sublimed, pulverized tungsten hexachloride (28.4 g, 0.072 mol) is loaded into an oven-dried powder addition funnel (Kontes) and connected to the Schlenk flask. The flask is cooled in a 15°C ice-water bath... 

Although commercially available (Aldrich), polymeric tungsten tetrachloride is routinely prepared by McCarley s method,7,15 which is given below. Tungsten hexachloride and tungsten hexacarbonyl (Strem) are used without further purification. Sodium-mercury amalgam (0.5 wt%) is prepared in a 500-mL two-necked round-bottomed flask equipped with a N2 gas inlet and a stopper, by adding 6.83 g (297 mmol) of sodium metal in small pieces ( 0.1-0.2 cm3) to 100 mL of mercury. 

Preparation of Molybdenum Pentachloride and Tungsten Hexachloride. Perform the experiment in a fume cupboardX) Assemble an apparatus as shown in Fig. 131. Pour a little concentrated sulphuric acid into wash bottles 1, 2, and 3. Put a layer of glass wool... 

Fig. 131. Apparatus for preparing molybdenum pentachloride and tungsten hexachloride...

Fill the apparatus with chlorine and perform chlorination of the molybdenum, heating the place of the tube where the metal is with the flame of a burner to 200-300 °C. What colour do molybdenum pentachloride and tungsten hexachloride have If oxychlorides are produced together with the molybdenum(V) or tungsten(VI) chlorides, distil them off in a chlorine stream. Transfer the product into a weighed test tube with a stopper, weigh it, and hand it in to your instructor. Calculate the yield in per cent. 

Test the reaction of molybdenum pentachloride (tungsten hexachloride) with water. What is observed What class of chemical compounds should the molybdenum and tungsten chlorides be related to ... 

In die last 10 years or so an exciting new strategy has emerged for the formation of carbon-carbon double bonds, namely olefin metathesis. This work grew out of the development of Ziegler-Natta catalysts for die polymerizarion of cyclic olefins. It was found that when 2-pentene was treated with a catalyst prepared from tungsten hexachloride and ethylaluminum dichloride, a mixture of 2-pentene, 2-butene, and 3-hexene was produced in minutes at room temperature (rt) ... 

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