Selenium hexasulfide

Selenium hexasulfide is a chemical compound with the chemical formula Se₂S₆. 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.^[2]

Quick facts Names, Identifiers ...

Selenium hexasulfide^[1]

1,2-Selenium hexasulfide 1,3-Selenium hexasulfide
1,4-Selenium hexasulfide 1,5-Selenium hexasulfide
Names
Other names Diselenacyclooctasulfane Diselenaoctathiocane Diselenium hexasulfide
Identifiers
CAS Number	75926-26-0 Y
3D model (JSmol)	1,2: Interactive image 1,5: Interactive image
ChemSpider	1,2: 9296780 1,5: 9057901
PubChem CID	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	Se2S6
Molar mass	350.30 g·mol−1
Appearance	orange needles
Density	2.44 g/cm3
Melting point	121.5 °C (250.7 °F; 394.6 K)
Solubility	soluble in carbon disulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Close

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).^[3] 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 cyclooctaselenium Se₈ and all other eight-member cyclic selenium sulfides, except selenacyclooctasulfane SeS₇, and several six- and seven-membered rings.^[2]