Tungsten hexachloride

Tungsten hexachloride is a tungsten coordination entity.
Tungsten(VI) chloride, WCl6, is a dark violet blue species that exists as a volatile solid under standard conditions. It is an important starting reagent in the preparation of tungsten compounds. As a d0 ion, W(VI) forms diamagnetic derivatives. WCl6 is octahedral with equivalent W-Cl distances of 2.24-2.26 .
dark grey-violet crystalline powder. Tungsten(VI) chloride is a blue-black solid at room temperature. At lower temperatures, it turns into wine red. A red form of the compound can be formed by quickly condensing its vapor, which transforms to the blue-black form on gentle heating. It is easily hydrolyzed, even by moist air, giving the orange oxychlorides WOCl4 and WO2Cl2, and then, tungsten trioxide. WCl6 is soluble in carbon disulfide, carbon tetrachloride, and phosphorus oxychloride. Methylation with trimethylaluminum forms hexamethyl tungsten.
Sublime it in a stream of Cl2 in a high temperature furnace and collect it in a receiver cooled in a Dry Ice-acetone bath in an inert atmosphere because it is sensitive to moisture. It is soluble in CS2, CCl4, CHCl3, POCl3, *C6H6, pet ether and Me2CO. Its solutions decompose on standing. Good crystals can be obtained by heating WCl6 in CCl4 to 100o in a sealed tube, followed by slow cooling (tablets of four-sided prisms). Store it in a desiccator over H2SO4 in the dark. [Leitzke & Holt Inorg Synth III 163 1950, Parterfield & Tyree Inorg Synth IX 133 1967, Hein & Herzog in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol II p 1420 1965.]