Arsenic triiodide

Arsenic Triiodide

Arsenic triiodide is a chemical compound with the formula AsI₃. It is a dark red solid that is highly soluble in water and other polar solvents. This compound is of interest in various fields, including chemistry and materials science, due to its unique properties and potential applications.

Structure and Properties

Arsenic triiodide is a molecular compound, consisting of one arsenic atom covalently bonded to three iodine atoms. The molecular geometry of AsI₃ is trigonal pyramidal, similar to that of other arsenic trihalides. The As-I bond length is approximately 2.55 Å.

The compound is known for its deep red color and crystalline form. It is relatively volatile and sublimes upon heating. Arsenic triiodide is sensitive to light and moisture, which can lead to its decomposition.

Synthesis

Arsenic triiodide can be synthesized by the direct reaction of elemental arsenic and iodine:

\[ \text{2 As} + \text{3 I}_2 \rightarrow \text{2 AsI}_3 \]

This reaction is typically carried out in a controlled environment to prevent contamination and ensure the purity of the product.

Applications

While arsenic triiodide itself is not widely used in industrial applications, it serves as a precursor for the synthesis of other arsenic-containing compounds. It is also used in research settings to study the properties of arsenic halides and their interactions with other substances.

Safety and Handling

Arsenic triiodide is highly toxic and should be handled with extreme care. It poses significant health risks if ingested, inhaled, or absorbed through the skin. Proper protective equipment, such as gloves and goggles, should be worn when handling this compound. It should be stored in a cool, dry place, away from light and moisture.

Also see

• Arsenic
• Iodine
• Arsenic trichloride
• Arsenic tribromide
• Halides