Pentacarbonyl thiocarbonyl tungsten

An apparatus consisting of a 1000-mL, three-necked flask fitted with a mechanical stirrer and reflux condenser is flushed with nitrogen for several minutes. A positive nitrogen pressure is maintained thereafter by a mineral oil bubbler connected to a T-tube in the gas line between the nitrogen cylinder and the 

After the amalgam is cooled, 400 mL of tetrahydrofuran (THF) distilled from lithium tetrahydridoaluminate is added to the flask, followed by 50.0 g (142 mmole) of W(CO)6. Caution. The THF should be checked for peroxide and high water content before LiAlH4 is added. The distillation procedure is given in Reference 6. 

An electric heating mantle is then fitted under the flask, and the mixture is vigorously stirred and heated to reflux under nitrogen for 12-18 hours. After cooling to room temperature, a positive nitrogen pressure is maintained while the mechanical stirrer is replaced with a glass stopper. 

The funnel is then placed on a 2000-mL, single-necked, round bottomed flask 

A water-cooled sublimation probe with a vacuum inlet, similar to that shown in Reference 8, is then inserted into the flask, which is immersed in an oil bath at 50-60°. The contents are sublimed under a static vacuum (i.e., the apparatus is closed after being evacuated), with occasional removal of the sublimate from the probe. Approximately 10-15 g of yellow crystals, a mixture of W(CO)6 and 3-6 g of W(CO)5(CS), is obtained. Much of the W(CO)6 may be removed by dissolving the yellow solid in approximately 400 mL of warm hexane and allowing the solution to cool to 0° in a refrigerator. The solution is decanted from the pale-yellow crystals [mainly W(CO)6] and evaporated to dryness to yield 4-7 g of a mixture that is generally 60-80% W(CO)s(CS). 

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