Diethyl zinc
From Wikipedia, the free encyclopedia
Diethyl zinc or 'DEZ' is a synthetic organometallic compound, the first organozinc compound discovered. It can be synthesised by the reaction of iodoethane with finely-divided zinc metal, under inert gas to avoid explosion - like many organometallics, it reacts violently with air and water.
Its reactivity meant that it was used in small quantities as a hypergolic liquid rocket fuel -- it ignites on contact with oxidiser, so the rocket motor need only contain a pump, rather than a spark source for ignition.
Diethyl zinc was also investigated for a period of many years by the United States Library of Congress as a potential means of deacidification of books printed on wood pulp paper. Initial experiments involved placing books within a vacuum chamber and dousing them with a vapor of diethyl zinc. Results were initially promising, showing the pH of the books to be reduced 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 and also caused the bindings and boards to split and warp. There was also some evidence of the pages being physically weakened, even as their acidity was reduced.
Most infamously, the final prototype suffered damage in a series of explosions from contact between trace amounts of diethyl zinc with moisture in the chamber. Engineers assigned to the project were unable to account for large volumes of the chemical after the process was completed and, unable to safely dismantle the device, a demolition team from the United States Army had to be called in to destroy the device with explosives. When the charges were detonated, the "missing" DEZ caused a cataclysmic explosion. As a result of this catastrophe, the Library of Congress has abandoned all investigation of DEZ as a potential deacidification agent.
[edit] See also
[edit] External links
- Double Fold: Libraries and the Assault on Paper A nonfiction book by novelist Nicholson Baker which includes several chapters on the Library of Congress' ill-fated diethyl zinc experiments.
