Dioxin
From Wikipedia, the free encyclopedia
 |
This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. |
Dioxin is a heterocyclic organic compound with the chemical formula C4H4O2. There are two isomers, 1,2-dioxin (or o-dioxin) and 1,4-dioxin (or p-dioxin). Their chemical structures are shown at right. The ortho isomer 1,2-dioxin is very unstable due to its peroxide-like characteristics.
The known properties of 1,4-dioxin are listed in the infobox to the right.
| 1,4-dioxin | |
|---|---|
 |
|
| IUPAC name | 1,4-dioxin |
| Other names | p-dioxin, dioxin |
| Identifiers | |
| CAS number | [290-67-5] |
| Properties | |
| Molecular formula | C4H4O2 |
| Molar mass | 84.07 g/mol |
| Appearance | Colorless liquid |
| Boiling point |
75°C (348°K) |
| Hazards | |
| EU classification | Toxic (T) |
| Main hazards | highly flammable |
| Related compounds | |
| Related compounds | dibenzodioxin |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
|
1,4-dioxin can be prepared by cycloaddition, namely by the Diels-Alder reaction. [1]
[edit] Other meanings (See other articles)
The word dioxin can also in a general way refer to compounds whose molecules have a dioxin core skeletal structure with substituent molecular groups attached to it. For example, dibenzo-p-dioxin is a compound whose structure consists of two benzo- groups fused onto a p-dioxin ring as shown below (see also Dibenzodioxin).
Because of their extreme importance as environmental pollutants, current scientific literature uses the name dioxins commonly for simplification to denote the chlorinated derivatives of dibenzo-p-dioxin, more precisely the polychlorinated dibenzodioxins (PCDDs). The polychlorinated dibenzodioxins, which can also be classified in the family of halogenated organic compounds, have been shown to bioaccumulate in humans and wildlife due to their lipophilic properties, and are known teratogens, mutagens, and carcinogens. References under the main article on polychlorinated dibenzodioxins.
Additionally, sometimes with dioxins a similar, but unrelated compound type the polychlorinated dibenzofurans of like importance are also implied.
[edit] Toxicity
Some Dioxin derivatives are known to increase the likelihood of cancer (See above under Other meanings). Scientists are working to establish their exact toxicity. The job is made difficult because we are not dealing with pure chemicals, but a mixture, and toxicity depends on the particular molecular arrangement of the compound, that of the highest toxicity is the 2,3,7,8-tetrachloro-para-dibenzo dioxin (pictured here as well). When people say dioxins, they often refer to these chlorinated derivatives, not the compound described in this article. These cases are discussed in detail in the article on Polychlorinated dibenzodioxin or PCDD but the toxicity of even some of these is disputed. The vietnami veterans case, the Soveso case, and Lushchenko's chloracne case and more are all discussed in that article. Another group of compounds of similar toxicity to that of the PCDD's are the polychlorinated dibenzofurans, their toxicity is also discussed with Dioxin derivatives, sometimes calling them all erroneously dioxins.
[edit] References
- ^ R. Alan Aitken, J. I. G. Cadogan and Ian Gosneya (1994). "Effect of ring strain on the formation and pyrolysis of some Diels–Alder adducts of 2-sulfolene (2,3-dihydrothiophene 1,1-dioxide) and maleic anhydride with 1,3-dienes and products derived therefrom". J. Chem. Soc., Perkin Trans. 1: 927 - 931. doi:.
