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IUPAC name
Other names
Dieldrin, HEOD
3D model (JSmol)
ECHA InfoCard 100.000.440
  • ClC5(Cl)[C@]3(Cl)C(\Cl)=C(\Cl)[C@@]5(Cl)[C@H]4[C@H]1C[C@H]([C@@H]2O[C@H]12)[C@@H]34
Molar mass 380.91 g/mol
Appearance colorless to light tan crystals
Density 1.75 g/cm3
Melting point 176 to 177 °C (349 to 351 °F; 449 to 450 K)
Boiling point 385 °C (725 °F; 658 K)
Main hazards potential carcinogen[1]
Flash point noncombustible
U.S. Permissible
exposure limit (PEL)
TWA 0.25 mg/m3 [skin][1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Dieldrin is a chlorinated hydrocarbon originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin. Aldrin reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to form dieldrin which is the active compound. Both dieldrin and aldrin are named after the Diels-Alder reaction which is used to form aldrin from a mixture of norbornadiene and hexachlorocyclopentadiene.

Dieldrin was developed as an alternative to DDT and has proved to be a highly effective insecticide. It was very widely used during the 1950s to early 1970s. Endrin is a stereoisomer of dieldrin.

However, it is an extremely persistent organic pollutant; it does not degrade easily. Furthermore, it tends to biomagnify as it is passed along the food chain. Long-term exposure has proven toxic to a very wide range of animals including humans. For this reason it is now banned in most of the world.

It has been linked to health problems such as Parkinson's disease, breast cancer, and immune, reproductive, and nervous system damage. It can also adversely affect testicular descent in the fetus if a pregnant woman is exposed to Dieldrin.

Dieldrin is listed in the Stockholm Convention on Persistent Organic Pollutants.

Synthesis[change | change source]

It can be formed from the synthesis of hexachloro-1,3-cyclopentadiene with norbornadiene in a Diels-Alder reaction, followed by epoxidation of the norbornene ring.[2]

Synthesis of Dieldrin via a Diels-Alder reaction

Dieldrin is named after Otto Paul Hermann Diels, the co-inventor of the Diels-Alder reaction.

References[change | change source]

  1. 1.0 1.1 1.2 NIOSH Pocket Guide to Chemical Hazards. "#0206". National Institute for Occupational Safety and Health (NIOSH).
  2. Jubb, A. H. (1975). Basic Organic Chemistry, Part 5 Industrial products. London: Wiley. ISBN 0-471-85014-4.