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Diethylzinc
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Diethylzinc (C2H5)2Zn, or DEZ, is an organozinc compound composed of zinc bonded to two ethyl groups. This colourless liquid is an important reagent in organic chemistry and available commercially as solutions of hexanes, heptane, or toluene.
lass="link1" onMouseover='showByLink("m7367263",this)' onMouseout='hide("m7367263")'href="http://www.absoluteastronomy.com/topics/Edward_Frankland">Edward Frankland first reported the compound in 1848 from zinc and ethyl iodide, the first organozinc compound discovered. He improved the synthesis by using diethyl mercury as starting material The contemporary synthesis consists of the reaction of a 1:1 mixture of ethyl iodide and ethyl bromide with a "zinc-copper couple," a source of reactive zinc.
hylzinc is used in organic synthesis as a source of the ethyl synthon in addition reactions to carbonyl groups.
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Encyclopedia
Diethylzinc (C2H5)2Zn, or DEZ, is an organozinc compound composed of zinc bonded to two ethyl groups. This colourless liquid is an important reagent in organic chemistry and available commercially as solutions of hexanes, heptane, or toluene.
Synthesis
Edward Frankland first reported the compound in 1848 from zinc and ethyl iodide, the first organozinc compound discovered. He improved the synthesis by using diethyl mercury as starting material The contemporary synthesis consists of the reaction of a 1:1 mixture of ethyl iodide and ethyl bromide with a "zinc-copper couple," a source of reactive zinc.
Reactions
Diethylzinc is used in organic synthesis as a source of the ethyl synthon in addition reactions to carbonyl groups. It is less nucleophilic than ethyllithium and the related Grignard reagent. For example in the asymmetric addition to benzaldehyde and imines.
With diiodomethane it forms a Simmons-Smith reagent.
Other uses
Because of its high reactivity toward air, it was used in small quantities as a hypergolic or "self igniting" liquid rocket fuel -- it ignites on contact with oxidiser, so the rocket motor need only contain a pump, without a spark source for ignition.
Diethylzinc was also investigated for a time by the United States Library of Congress as a potential means of mass deacidification of books printed on wood pulp paper. Initial experiments involved placing books within a vacuum chamber and exposing them to diethylzinc vapour. In theory, the vapour would react with acid residues in the paper, neutralizing them and leaving only slightly alkaline zinc oxide residues in the paper. Results were initially promising, showing the pH of the paper to be increased to 7.5. Larger-scale experiments did not go as well; prototypes built for the Library of Congress by Northrup left "tide marks" on the pages, caused the bindings and boards to split and warp, and left unpleasant odours. There was also some evidence of the pages being physically weakened, even as their acidity was reduced. In addition, it became clear that any large-scale deacidification process involving diethylzinc would require the transport by truck of enormous volumes of the chemical, which could not be done safely due to its volatility.
Most infamously, the final prototype suffered damage in a series of explosions from contact between trace amounts of diethylzinc and water vapor in the chamber. The project was abandoned.
In microelectronics, diethylzinc is used as a doping agent.
Safety
Diethylzinc reacts violently with water and easily ignites upon contact with air. It should therefore be handled using inert atmosphere techniques.
External links
- Demonstration of the ignition of Diethylzinc in air
- Diethylzinc, 15 wt.% solution in hexane [https://fscimage.fishersci.com/msds/46190.htm MSDS commercial supplier]
- Diethylzinc purum
- Diethylzinc
- Diethylzinc
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