Diethylzinc

Description

Diethyl zinc is an organometal compound and is a dangerous fire hazard. It spontaneously ignites in air and reacts violently with water, releasing flammable vapors and heat. It is a colorless, pyrophoric liquid with a specific gravity of 1.2, which is heavier than water, so it will sink to the bottom. It decomposes explosively at 248°F (120°C). It has a boiling point of 243°F (117°C), a flash point of ?20°F (?28°C), and a melting point of ?18°F (?27°C). The four-digit UN identification number is 1366. The NFPA 704 designation is health 3, flammability 4, and reactivity 3. The white space at the bottom of the diamond has a W with a slash through it to indicate water reactivity. Primary uses of diethyl zinc are in the polymerization of olefins, high-energy aircraft, and missile fuel and in the production of ethyl mercuric chloride.

Chemical Properties

Clear colorless solution. M.p. -30°C, b.p. (760 mm.) 117.6°C,(30 mm.) 27°C, (4 mm.) 0°C; d (20°C) 1.207, (8°C) 1.245. Resistant to CO3; ignites in air. Decomposes extremely violently in H3O, forming Zn(OH)a and C3H8. Soluble in ether.

Uses

Diethylzinc solution can be used in the synthesis of:

• Bis(pyridylpyrrolyl)zinc luminescent complexes.
• A versatile building block, 5-(ketoaryl)thiazole.
• Zn_xCd_1-xSe nanocrystals having high luminescence properties.

General Description

Diethylzinc is a pyrophoric liquid with a garlic-like odor. Diethylzinc is stable when Diethylzinc is shipped in sealed tubes with carbon dioxide. Diethylzinc may decompose violently in water and ignite spontaneously with air. Diethylzinc is toxic by ingestion. If exposed to heat or flame, containers of Diethylzinc may explode. Diethylzinc is used as an aircraft fuel.

Air & Water Reactions

Highly flammable. Ignites in air with a blue flame giving off a peculiar garlic-like odor, [Merck, 11th ed., 1989]. Diethyl zinc is spontaneously flammable in air, [Douda(1966)]. Reacts violently with water to form flammable ethane gas, [Brauer(1965)].

Reactivity Profile

Diethylzinc is pyrophoric in air, Diethylzinc ignites instantaneously. Diethylzinc reacts explosively with alcohols (methanol, ethanol), bromine, chlorine or liquefied sulfur dioxide [Houben-Weyl, 1973, 13.2a, p. 855, 757, 709]. Reaction with water, nitro compounds, arsenic trichloride, phosphorus trichloride is violent [Bretherick, 5th ed., 1995, p. 587].

Health Hazard

Inhalation of mist or vapor causes immediate irritation of nose and throat; excessive or prolonged inhalation of fumes from ignition or decomposition may cause ``metal fume fever'' (sore throat, headache, fever, chills, nausea, vomiting, muscular aches, perspiration, constricting sensation in lungs, weakness, sometimes prostration); symptoms usually last 12-24 hrs., with complete recovery in 24-48 hrs. Eyes are immediately and severely irritated on contact with liquid, vapor, or dilute solution; without thorough irrigation, cornea may be permanently damaged. Moisture in skin combines with chemical to cause thermal and acid burns; tissue may be scarred without prompt treatment. Ingestion is unlikely but would cause immediate burns at site of contact; pain, nausea, vomiting, cramps, and diarrhea may follow; if untreated, tissue may become ulcerated.

Fire Hazard

Diethylzinc ignites spontaneously in air, burning with a blue flame. Reactions with water and lower alcohols can be violent.Violent reactions can occur with halogens, halogenated hydrocarbons, nitroorganics, oxidizers, sulfur dioxide, and chlorides of phosphorus, arsenic, and antimony. With the latter compounds, diethylzinc forms pyrophoric triethylphosphine, triethyl arsine, and triethylstibine, respectively.

Safety Profile

Presumed to be a poison. Ignites spontaneously in air. Dangerously flammable by spontaneous chemical reaction in air, or with oxidzing materials. A dangerous explosion hazard Explosive reaction with alkenes + diodomethane, sulfur dioxide. Reacts violently with bromine, water, nitro compounds. Igmtes on contact with air, ozone, methanol, or hydrazine. Reacts violently with nonmetal halides (e.g., arsenic trichloride or phosphorus trichloride) to produce pyrophoric triethyl arsine or triethyl phosphine. To fight fire, do not use water, foam, or halogenated extinguishing agents. Use dry materials, such as graphite, sand, etc. When heated to decomposition it emits toxic fumes of ZnO. See also ZINC COMPOUNDS.

Synthesis

Diethylzinc is obtained by the reaction of Zn and C2H5Ⅰ to produce C2H5ZnⅠ, which is then distilled under inert gas conditions.
Zn + C2H5Ⅰ = C2H5ZnⅠ; 2C2H5ZnⅠ = Zn(C2H5)2+ ZnⅠ2.