Selenophene

Selenophene is an unsaturated organic compound containing a five member ring with selenium with formula C4H4Se. It is a metallole with reduced aromatic character compared to thiophene.

Selenophene
Identifiers
103223
ChEBI
ChemSpider
ECHA InfoCard 100.157.009
100994
Properties
C4H4Se
Molar mass 131.047 g·mol−1
Density 1.52
Melting point −38 °C (−36 °F; 235 K)
Boiling point 110 °C (230 °F; 383 K)
1.58
Hazards
GHS pictograms
GHS Signal word Danger
H225, H301, H331, H373, H400, H410
P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P273, P280, P301+310, P303+361+353, P304+340, P311, P314, P321, P330, P370+378, P391, P403+233, P403+235, P405
Related compounds
Related more saturated
 selenolane
2-selenolene
3-selenolene
Related compounds
 furan
thiophene
tellurophene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Nomenclature

Atoms in selenophene are numbered sequentially around the ring, starting with the selenium atom as number 1 following normal systematic nomenclature rules. Oxidized forms include selenophene 1,1-dioxide.[1] Related ring structures include those with only one double bond (2-selenolene and 3-selenolene) and the fully saturated structure selenolane.[2]

Production

Although Ida Foa claimed to have made selenophene in 1909, the first confirmed production was by Mazza and Solazzo in 1927. They heated acetylene and selenium together at about 300 °C. The selenium burst into flame, and up to 15% selenophene was formed, along with selenonaphthene.[2] Another way to make it is from furan heated with hydrogen selenide and aluminium at 400 °C.[3]

Substituted selenophenes can be made using a Fiesselman procedure in which a β-chloro-aldehyde reacts with sodium selenide, and then ethyl bromoacetate.[3]

Properties

The selenophene molecule is flat and aromatic.[3] Being aromatic, it undergoes electrophilic substitution reactions at the 2- or 2,5-positions.[3] These reactions are slower than that of furan, but faster than thiophene.[3]

References
  1. Pelkey, E. T. (2008). Katritzky, Alan R.; Ramsden, Christopher A.; Scriven, Eric F. V.; Taylor, Richard J. K. (eds.). Comprehensive Heterocyclic Chemistry III. Oxford: Elsevier. pp. 975–1006. doi:10.1016/B978-008044992-0.00313-8. ISBN 9780080449920.
  2. Hartough, H. D. (2009). Thiophene and Its Derivatives. John Wiley & Sons. ISBN 9780470188026.
  3. Eicher, Theophil; Hauptmann, Siegfried; Speicher, Andreas (2013). The Chemistry of Heterocycles: Structures, Reactions, Synthesis, and Applications. John Wiley & Sons. pp. 69–70. ISBN 9783527669868.
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