Selenophene

Selenophene
Names
	Preferred IUPAC name Selenophene
Identifiers
CAS Number	288-05-1;
Beilstein Reference	103223
ChEBI	CHEBI:30857;
ChemSpider	119907;
ECHA InfoCard	100.157.009
Gmelin Reference	100994
PubChem CID	136130;
UNII	UYZ3M5T8L7;
CompTox Dashboard (EPA)	DTXSID20182978 ;
	InChI InChI=1S/C4H4Se/c1-2-4-5-3-1/h1-4H Key: MABNMNVCOAICNO-UHFFFAOYSA-N;
	SMILES C1=C[Se]C=C1;
Properties
Chemical formula	C4H4Se
Molar mass	131.047 g·mol−1
Appearance	colorless liquid
Density	1.52 g/cm3
Melting point	−38 °C (−36 °F; 235 K)
Boiling point	110 °C (230 °F; 383 K)
Refractive index (nD)	1.58
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H301, H331, H373, H410
Precautionary statements	P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P273, P280, P301+P310, P303+P361+P353, P304+P340, P311, P314, P321, P330, P370+P378, P391, P403+P233, P403+P235, P405, P501
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

Selenophene is an organic compound with the chemical formula C₄H₄Se. It is an unsaturated compound containing a five-member ring with four carbon atoms and one selenium atom. It is a selenium analog of furan C₄H₄O and thiophene C₄H₄S. A colorless liquid, it is one of the more common selenium heterocycles.

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.^[2] Related ring structures include those with only one double bond (2-selenolene and 3-selenolene) and the fully saturated structure selenolane.^[3]

Production

Mazza and Solazzo reported the first confirmed synthesis in 1927. By treating selenium with acetylene and at about 300 °C yields up to 15% selenophene were obtained. Benzoselenophene (analogue of benzothiophene) was also produced.^[3]

Substituted selenophenes can be made using a Fiesselman procedure in which a β-chloro-aldehyde reacts with sodium selenide, and then ethyl bromoacetate.^[4]

Properties

The selenophene molecule is flat.^[4] Being aromatic, it undergoes electrophilic substitution reactions. As for thiophene, electrophiles tend to attack at the carbon positions next to the chalcogen. Such reactions are slower than that of furan, but faster than thiophene.^[4]

References

^ International Union of Pure and Applied Chemistry (2014). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. p. 141. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.
^ 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.
^ ^a ^b Hartough, H. D. (2009). Thiophene and Its Derivatives. John Wiley & Sons. ISBN 9780470188026.
^ ^a ^b ^c Eicher, Theophil; Hauptmann, Siegfried; Speicher, Andreas (2013). The Chemistry of Heterocycles: Structures, Reactions, Synthesis, and Applications. John Wiley & Sons. pp. 69–70. ISBN 9783527669868.

[1] International Union of Pure and Applied Chemistry (2014). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. p. 141. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.

[2] 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.

[taid-3] Hartough, H. D. (2009). Thiophene and Its Derivatives. John Wiley & Sons. ISBN 9780470188026.

[tcah-4] Eicher, Theophil; Hauptmann, Siegfried; Speicher, Andreas (2013). The Chemistry of Heterocycles: Structures, Reactions, Synthesis, and Applications. John Wiley & Sons. pp. 69–70. ISBN 9783527669868.

[1]

[2]

[3]

[4]