Tellurium tetrachloride

Description

Tellurium tetrachloride (TeCl4)

Overview
Tellurium tetrachloride is the covalently bonded compound of tellurium in the +4 oxidation state with four chlorine ligands. It is a moisture‑sensitive reagent that is used as a precursor for various tellurium compounds and in organic synthesis as a chlorinating/reagent.

• Formula: TeCl4
• Common name: Tellurium tetrachloride

Preparation (typical routes)

1. Direct chlorination of tellurium metal at elevated temperature:
   • Te + 2 Cl2 → TeCl4
2. Oxidation/chlorination of tellurium halide intermediates:
   • TeCl2 or TeO2 can be converted to TeCl4 under chlorine gas or in chlorinating environments.

Key properties

• Appearance: Often described as a colorless to pale yellow volatile liquid; it can be moisture sensitive.
• Stability: Reacts with water and oxygen in air; hydrolyzes upon contact with water to produce tellurium oxychloride species and HCl. Prolonged exposure to moisture can lead to TeO2 formation.
• Structure: In the gas phase it tends to be monomeric; in the solid state it can form polymeric aggregates or complexes depending on conditions.
• Reactivity: Acts as a chlorinating agent and a precursor for a variety of tellurium compounds.

Reactions to know

1. Synthesis (example):
   • Te + 2 Cl2 → TeCl4
2. Hydrolysis (high level):
   • TeCl4 reacts with water to give Te-containing oxychloride species and HCl; prolonged hydrolysis can yield TeO2.
3. Use in synthesis:
   • TeCl4 can be used to prepare organotellurium compounds via halide exchange or oxidative addition reactions in organic chemistry.

Typical uses

• Precursor for preparing tellurium(IV) compounds.
• Reagent in organotellurium chemistry and various chlorination steps.
• Intermediate in the preparation of tellurium oxides and oxychlorides.

Safety and handling

• Hazards: Corrosive and toxic; fumes can contain HCl during hydrolysis. Strong irritant to eyes, skin, and respiratory system.
• Storage: Keep dry and in a tightly sealed container under inert atmosphere (e.g., nitrogen or argon) to minimize hydrolysis.
• Handling tips: Work in a well‑ventilated fume hood; wear appropriate PPE (gloves, goggles, lab coat).