Dimethylzinc

Dimethylzinc, also known as DMZn or Zinc dimethyl, is a highly volatile, pyrophoric liquid that is used primarily in the chemical vapor deposition (CVD) of zinc-containing films and semiconductors. It is a compound of zinc with the formula Zn(CH₃)₂. This organozinc compound is significant in organic chemistry as a reagent, particularly in the synthesis of various organic compounds.

Properties

Dimethylzinc is a colorless, mobile liquid that exhibits extremely reactive properties. It spontaneously ignites upon exposure to air, making its handling and storage critical. The compound has a boiling point of 46°C and a density slightly less than that of water. It is soluble in hydrocarbons, which are often used as solvents for its applications.

Synthesis

The synthesis of dimethylzinc involves the reaction of zinc metal with methyl chloride or methyl iodide, typically in the presence of a lithium chloride catalyst. This process was first described in the 19th century and has undergone various improvements over the years. The reaction is highly exothermic and requires careful control to prevent accidents.

Applications

Dimethylzinc is primarily used in the deposition of zinc-containing films and semiconductors through chemical vapor deposition. It serves as a precursor for the growth of zinc oxide (ZnO) layers, which are essential in the fabrication of electronic devices, including solar cells, LEDs, and laser diodes. Additionally, it finds application in organic synthesis, where it is used to introduce methyl groups into organic molecules.

Safety

The handling of dimethylzinc requires strict safety measures due to its pyrophoric nature and the potential for explosive reactions with air or moisture. Protective equipment, including gloves and face shields, is mandatory. Storage in inert atmospheres and the use of specialized containers are also critical to prevent accidental ignition.

See Also

• Chemical vapor deposition
• Zinc oxide
• Organometallic chemistry
• Pyrophoricity