Tungsten dichloride dioxide, or tungstyl chloride is the chemical compound with the formula . It is a yellow solid. It is used as a precursor to other tungsten compounds. Like other tungsten halides, is sensitive to moisture, undergoing hydrolysis.
Preparation is prepared by ligand redistribution reaction from tungsten trioxide and tungsten hexachloride:
Using a two-zone tube furnace, a vacuum-sealed tube containing these solids is heated to 350 °C. The yellow product sublimes to the cooler end of the reaction tube. No redox occurs in this process. An alternative route highlights the oxophilicity of tungsten:
This reaction, like the preceding one, proceeds via the intermediacy of .
Structure Gaseous tungsten dichloride dioxide is a monomer. Solid tungsten dichloride dioxide is a polymer consisting of distorted octahedral W centres. The polymer is characterized by two short W-O distances, typical for a multiple W-O bond, and two long W-O distances more typical of a single or dative W-O bond.Jarchow, O.; Schröder, F.; Schulz, H. "Kristallstruktur und Polytypie von WO2Cl2" Zeitschrift für anorganische und allgemeine Chemie 1968, vol. 363, p. 345ff.
Related oxyhalides Tungsten forms a number of oxyhalides including , , . The corresponding bromides (, , ) are also known as is .Holleman, A. F.; Wiberg, E. Inorganic Chemistry Academic Press: San Diego, 2001. .
Reactions
is a Lewis acid, forming soluble adducts of the type , where L is a donor ligand such as bipyridine and dimethoxyethane. Such complexes often cannot be prepared by depolymerization of the inorganic solid, but are generated in situ from .K. Dreisch, C. Andersson, C. Stalhandske "Synthesis and structure of dimethoxyethane-dichlorodioxo-tungsten(VI)—a highly soluble derivative of tungsten dioxodichloride" Polyhedron 1991, volume 10, p. 2417.
reacts with tetraphenylphosphonium chloride to give (Ph = C6H5).
References