Selenium hexasulfide

Names Other names

Diselenacyclooctasulfane
Diselenaoctathiocane
Diselenium hexasulfide

Identifiers

CAS Number

75926-26-0

3D model (JSmol)

1,2: Interactive image
1,5: Interactive image

ChemSpider

1,2: 9296780
1,5: 9057901

PubChemCID

1,2: 11121651
1,5: 10882632

InChI

1,2: InChI=1S/S6Se2/c1-2-4-6-8-7-5-3-1
Key: GVMSZJKNEHYJTG-UHFFFAOYSA-N
1,5: InChI=1S/S6Se2/c1-3-7-5-2-6-8-4-1
Key: XHXZYRZXIYIDIG-UHFFFAOYSA-N

SMILES

1,2: S1SSS[Se][Se]SS1
1,5: S1S[Se]SSS[Se]S1

Properties

Chemical formula

Se₂S₆Molar mass350.30 g·mol Appearance orange needles Density2.44 g/cm Melting point121.5 °C (250.7 °F; 394.6 K) Solubilitysoluble in carbon disulfide

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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Selenium hexasulfide is a chemical compound with the chemical formulaSe₂S₆. Its molecular structure is an 8-membered ring, consisting of two selenium and six sulfur atoms (diselenacyclooctasulfane), analogous to the S₈ ring, an allotrope of sulfur (cyclooctasulfur or cyclooctasulfane), and other 8-membered rings of selenium sulfides with formula Se_nS_8−n.

There are several isomers depending on the relative placement of the selenium atoms in the ring: 1,2-diselenacyclooctasulfane (with the two Se atoms adjacent), 1,3-diselenacyclooctasulfane, 1,4-diselenacyclooctasulfane, and 1,5-diselenacyclooctasulfane (with the Se atoms opposite). It is an oxidizing agent.

The 1,2 isomer can be prepared by reaction of chlorosulfanes and dichlorodiselane with potassium iodide in carbon disulfide. The reaction produces also cyclooctaseleniumSe₈ and all other eight-member cyclic selenium sulfides, except selenacyclooctasulfane SeS₇, and several six- and seven-membered rings.