Selenium disulfide
From Wikipedia, the free encyclopedia
| Selenium disulfide | |
|---|---|
| IUPAC name |
Selenium disulfide
|
| Other names | Selenium(IV) sulfide |
| Identifiers | |
| CAS number | 7488-56-4  |
| PubChem | 24087 |
| MeSH | Selenium+sulfide |
| RTECS number | VS8925000 |
| ATC code | D01 |
| Properties | |
| Molecular formula | SeS2 |
| Molar mass | 143.09 g/mol |
| Appearance | orange |
| Melting point |
-249.5 °C, 24 K, -417 °F |
| Boiling point |
-112 °C, 161 K, -170 °F |
| Solubility in water | insoluble |
| Hazards | |
| EU Index | 034-002-00-8 |
| EU classification | Toxic (T) Dangerous for the environment (N) |
| R-phrases | R23/25, R33, R50/53 |
| S-phrases | (S1/2), S20/21, S28, S45, S60, S61 |
| NFPA 704 |
 0
2
0
|
| Related compounds | |
| Other anions | Selenium dioxide |
| Other cations | Tellurium disulfide |
| Related compounds | Selenium monosulfide |
| (what is this?) (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Selenium (IV) sulfide, also known as selenium sulfide, is an inorganic compound with the approximate formula SeS2. Both sulfur and selenium catenate (form chains and rings) readily, and mixtures of selenium and sulfur likewise give rise to numerous "alloys".[1] This compound is not an analogue of sulfur dioxide.
Contents |
[edit] Medicinal selenium disulfide
The material commercially called selenium disulfide is sold as an antifungal agent in shampoos for the treatment of dandruff and seborrheic dermatitis associated in the scalp with Malassezia genus fungi.[2][3][4] In the United States, a 1% strength is available over-the-counter, and a 2.5% strength is also available with a prescription. At the 2.5% strength, selenium disulfide is also used on the body to treat tinea versicolor, a type of fungal skin infection caused by a different species of Malassezia.
[edit] Chemical composition
Selenium disulfide has a composition that approximates to SeS2 and is sometimes called selenium sulfide. However as used in proprietary formulations it is not a pure chemical compound but is a mixture where the overall Se:S ratio is 1:2. The compounds are cyclic Se–S rings containing a variable number of S and Se atoms, SenS8−n.[1] Selenium disulfide can cause discoloration of the hair and alter the color of hair dyes. It may also discolor metallic jewellery.
[edit] Other selenium sulfides
Many selenium sulfides are known. A useful means for characterization is 77Se NMR spectroscopy. Chalcogen ring interconversion pathways.[5] Selenium monosulfide (SeS) is the only selenium compound so far identified as a carcinogen in animals.[6] Selenium monosulfide, along with elemental selenium and sulfur has been used in medicinal preparations in the past[7], causing confusion and contradiction[8] as to exactly what form selenium is in, in any given topical preparation.[9]
[edit] See also
- Zinc pyrithione, an antimicrobial agent used in some medicated shampoos.
- Selsun Blue, a shampoo with selenium disulfide as its active ingredient.
[edit] References
- ^ a b Cyclic selenium sulfides R. Steudel, R. Laitinen, Topics in Current Chemistry, (1982), 102, 177-197
- ^ Selenium(IV) sulfide - pharmacy codes search engine
- ^ Chemicals of Selenium .Se
- ^ Accessed Dec. 24, 2007
- ^ P. Pekonen, Y. Hiltunen, R. S. Laitinen, T. A. Pakkanen "Selenium-77 NMR spectroscopic study of the decomposition of 1,2,3,4,5-Se5S2 to 1,2,3,4,5,6-Se6S2 and 1,2,3,4-Se4S2" Inorg. Chem., 1991, 30, pp 3679–3682.doi:10.1021/ic00019a022
- ^ http://www.scorecard.org/chemical-profiles/html/selenium.html
- ^ Definition: selenium sulfide from Online Medical Dictionary
- ^ DrugBank: DB00971 (Selenium Sulfide)
- ^ selenium sulfide: Definition and Much More from Answers.com
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