How many ways to synthesize tungsten hexachloride?

How many ways to synthesize tungsten hexachloride?

Tungsten hexachloride (WCl6) is a typical compound of the transition metal tungsten. It is a dark blue or blue purple powder with good catalytic performance, good oxidation and reducibility. It can not only be used to produce other products of tungsten, but also as a catalyst for olefin polymerization. The main synthesis methods of WCl6 are as follows:

Tungsten trioxide & Tungsten powderpicture

Method 1: Tungsten trioxide (WO3) and hexachloropropane were placed in a round-bottomed flask, connected with a reflux condenser with a drying tube, heated with full stirring until WO3 was completely reacted and dissolved. After cooling, black crystals were generated, which were then filtered out with a glass filter, washed with dried carbon tetrachloride, vacuumed, and the organic solvents were removed. Finally, the products were sealed and stored.

Method 2: Tungsten powder was put into the quartz reaction tube, and the reaction was carried out at 1000℃ at the same time as chlorine gas. Then the target product sublimated and precipitated in the cold part of the reaction tube. If you want to make a large number of this product, you can connect the coarse reaction tube and the large size of the acceptor directly, and then between the furnace and the acceptor, wrapped with asbestos and chromium wire, heating not more than 350℃, the product accumulation in the reaction tube outlet near. Before and after the reaction, the air and chlorine gas in the reaction tube and receiver are thoroughly replaced with inert gas. If mixed with oxygen or moisture large air, it is easy to form tungsten oxychloride. If the byproducts mentioned above are mixed in the target product, they can be removed by heating because tungsten oxychloride is more volatile than tungsten hexachloride. However, when the temperature is higher than the boiling point of WCl6, it will cause the decomposition of WCl6.

Method 3: The tungsten trioxide and tungsten chloride were mixed, and then placed in the reaction tube, and then the tube was sealed under vacuum and heated in an environment of 175℃. After the reaction, the required product could be obtained.

Method four: First, screening large particle tungsten powder, chlorine gas through purification and preheating, screening large particle activated carbon through high temperature chlorine atmosphere for dehydration and deoxidation treatment; Second, tungsten powder reacts with purified high-temperature chlorine gas to produce WCl6 and tungsten chloride impurities; Thirdly, the processed activated carbon is filled in the refining furnace, the steam produced by the chlorination furnace and the purified high temperature chlorine gas are refined in the refining furnace, and the tungsten oxychloride and low-price tungsten chloride in the steam are reduced to tungsten hexachloride to obtain the refining steam; Fourth, the purified steam enters the receiver, the cooling water controls the temperature, and the high purity tungsten hexachloride powder is obtained.