Diméthylzinc

Dimethylzinc, also known as zinc methyl, DMZ, or DMZn, is an organozinc compound with the chemical formula . It belongs to the large series of similar compounds such as diethylzinc. It is formed by the action of methyl iodide on zinc or zinc-sodium alloy at elevated temperatures. Sodium assists the reaction of the zinc with the methyl iodide. Zinc iodide is formed as a byproduct. Dimethylzinc is a colorless mobile volatile liquid, which has a characteristic disagreeable garlic-like odor. It is a very reactive and strong reducing agent. It is soluble in alkanes and often sold as a solution in hexanes. The triple point of dimethylzinc is ± 0.02 K. The monomeric molecule of dimethylzinc is linear at Zn center and tetragonal at C centers. Inhalation of dimethylzinc mist or vapor causes immediate irritation of the upper respiratory tract, and may cause pneumonia and death. Eyes are immediately and severely irritated and burned by liquid, vapor, or dilute solutions. If not removed by thorough flushing with water, this chemical may permanently damage the cornea, eventually causing blindness. If dimethylzinc contacts the skin, it causes thermal and acid burns by reacting with moisture on skin. Unless washed quickly, skin may be scarred. Ingestion, while unlikely, also causes immediate burns. Nausea, vomiting, cramps, and diarrhea may follow, and tissues may ulcerate if not promptly treated. Upon heating, dimethylzinc vapor decomposes to irritating and toxic products. Contact of dimethylzinc with oxidants may form explosive peroxides. Dimethylzinc oxidises in air very slowly, producing methylzinc methoxide . Dimethylzinc is very pyrophoric and can spontaneously ignite in air. It burns in air with a blue flame, giving off a garlic-like odor. The products of decomposition (fire smoke) include zinc oxide, which itself is not toxic, but its fumes can irritate lungs and cause metal fume fever, severe injury, or death. Dimethylzinc fire must be extinguished with dry sand.