Selenium disulfide
| Names | |
|---|---|
| IUPAC name
Selenium disulfide | |
| Other names
Selenium sulfide | |
| Identifiers | |
7488-56-4  | |
| ChEMBL | ChEMBL1200680  |
| MeSH | Selenium+sulfide |
| PubChem | 24087 |
| RTECS number | VS8925000 |
| |
| Properties | |
| SeS2 | |
| Molar mass | 143.09 g/mol |
| Appearance | orange to brown powder |
| Odor | faint |
| Density | 3 g/cm3 |
| Melting point | 111 °C (232 °F; 384 K) |
| Boiling point | 118 to 119 °C (244 to 246 °F; 391 to 392 K) (decomposes) |
| negligible | |
| Solubility | soluble in ammonium monosulfide negligible in organic solvents |
| Acidity (pKa) | 2-6 |
| Pharmacology | |
| D01AE13 (WHO) | |
| Hazards | |
| EU classification (DSD) |
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 | |
| Related compounds | |
| Other anions |
Selenium dioxide Selenic acid Selenous acid |
| Other cations |
Hydrogen sulfide |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| verify (what is ?) | |
| Infobox references | |
Selenium disulfide is an inorganic compound with the approximate formula SeS2. Both sulfur and selenium catenate, that is 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.
It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system.[2]
Medical uses
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.[3][4][5] 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.
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.
Other selenium sulfides
Many selenium sulfides are known. A useful means for characterization of their structures and interconversions is 77Se-NMR spectroscopy.[6] Selenium monosulfide (SeS) is the only selenium compound so far identified as a carcinogen in animals.[7] Selenium monosulfide, along with elemental selenium and sulfur, has been used in medicinal preparations in the past,[8] causing confusion and contradiction[9] as to exactly what form selenium is in any given topical preparation.[10]
See also
- Zinc pyrithione, an antimicrobial agent used in many off the shelf shampoos
- Selsun Blue, a shampoo with selenium disulfide as its active ingredient
- Ketoconazole, another antifungal agent used in medicated shampoos
References
- 1 2 Cyclic selenium sulfides R. Steudel, R. Laitinen, Topics in Current Chemistry, (1982), 102, 177-197
- ↑ "19th WHO Model List of Essential Medicines (April 2015)" (PDF). WHO. April 2015. Retrieved May 10, 2015.
- ↑ Selenium(IV) sulfide - pharmacy codes search engine
- ↑ Chemicals of Selenium .Se
- ↑ Accessed Dec. 24, 2007
- ↑ Pekonen, Pentti.; Hiltunen, Yrjō; Laitinen, Risto S.; Pakkanen, Tapani A. (1991). "Chalcogen ring interconversion pathways. 77Se 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". Inorganic Chemistry. 30 (19): 3679. doi:10.1021/ic00019a022.
- ↑ "selenium compounds".
- ↑ "Definition: selenium sulfide from Online Medical Dictionary".
- ↑ "DrugBank: DB00971 (Selenium Sulfide)".
- ↑ "selenium sulfide: Definition and Much More from Answers.com".
Further reading
- Danby, FW; Maddin, WS; Margesson, LJ; Rosenthal, D (December 1993). "A randomized, double-blind, placebo-controlled trial of ketoconazole 2% shampoo versus selenium sulfide 2.5% shampoo in the treatment of moderate to severe dandruff". Journal of the American Academy of Dermatology. 29 (6): 1008–12. doi:10.1016/0190-9622(93)70282-x. PMID 8245236.
- Grover, R. W. (1956). "Diffuse Hair Loss Associated with Selenium (Selsun) Sulfide Shampoo". JAMA: the Journal of the American Medical Association. 160 (16): 1397. doi:10.1001/jama.1956.02960510023006.
- Givens, T. G.; Murray, M. M.; Baker, R. C. (1995). "Comparison of 1% and 2.5% Selenium Sulfide in the Treatment of Tinea Capitis". Archives of Pediatrics and Adolescent Medicine. 149 (7): 808–11. doi:10.1001/archpedi.1995.02170200098016. PMID 7795774.
- Ransone, James W.; Scott, Norman M.; Knoblock, Edward C. (1961). "Selenium Sulfide Intoxication". New England Journal of Medicine. 264 (8): 384. doi:10.1056/NEJM196102232640806.
- Laitinen, Risto S.; Pakkanen, Tapani A. (1987). "77Se NMR spectroscopic characterization of selenium sulfide ring molecules SenS8-n". Inorganic Chemistry. 26 (16): 2598. doi:10.1021/ic00263a010.