Tungsten Dichloride

Introduction

Name: Tungsten Dichloride
CAS: 13470-12-7
Formula: WCl₂
Olecular Weight： 254.76
Density: 5.436g/cm³

Nature

Tungsten dichloride is an amorphous powder with light gray, easily forming octahedron groups; it is very unstable in air and easily oxidized. Tungsten dichloride can be decomposed at 500 ℃, and even water oxidized which shows releasing hydrogen. Tungsten dichloride can be dissolved in hydrochloric acid, ethanol and ether.

Storage

Tungsten dichloride can be saved in the condition with excess of hydrogen chloride.

Preparation

In the tungsten-chloro-oxygen system compounds, such as dichloride tungsten, the higher position the oxygen is, the higher the WO2Cl2 mixed vapor content, for obtaining tungsten dichloride, oxygen-bit must be reduced, and ensure adequate reducing atmosphere. Therefore, scheelite or wolframite chloride, carbon is often added as a reducing agent.

There are two ways to prepare dichloride tungsten: First, restore aluminum tetrachloride in sodium aluminate melt tungsten hexachloride generation; second, disproportionation of tungsten tetrachloride in the 400~450℃.

Carrying out reaction in vacuo and seal borosilicate glass tube. Place tungsten tetrachloride into the end of the tube and heated to 450~500℃, however the other end is kept at room temperature. As the reaction proceeds, tungsten pentachloride can condense on the cold end portion of the tube, thus to separate the tungsten dichloride. Reaction equation: 3WCl ₄ (s)→WCl₂ (s)+2WCl ₅ (g).

Application

Tungsten dichloride is an important raw material for new application fields.