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;
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
Density	1.52
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	; ;
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 unsaturated organic compound containing a five member ring with selenium with formula C₄H₄Se. It is a metallole with reduced aromatic character compared to thiophene.

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 ( and ) and the fully saturated structure .^[3]

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 .^[3] Another way to make it is from furan heated with hydrogen selenide and aluminium at 400 °C.^[4]

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 and aromatic.^[4] Being aromatic, it undergoes electrophilic substitution reactions at the 2- or 2,5-positions.^[4] These 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 ^d ^e 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.

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