Carbon diselenide explained

Carbon diselenide is an inorganic compound with the chemical formula . It is a yellow-orange oily liquid with pungent odor. It is the selenium analogue of carbon disulfide and carbon dioxide . This light-sensitive compound is insoluble in water and soluble in organic solvents.

Synthesis, structure and reactions

Carbon diselenide is a linear molecule with D_∞h symmetry. It is produced by reacting selenium powder with dichloromethane vapor near 550 °C.^[1]

It was first reported by Grimm and Metzger, who prepared it by treating hydrogen selenide with carbon tetrachloride in a hot tube.^[2]

Like carbon disulfide, carbon diselenide polymerizes under high pressure. The structure of the polymer is thought to be a head-to-head structure with a backbone in the form of .^[3] The polymer is a semiconductor with a room-temperature conductivity of 50 S/cm.

In addition, carbon diselenide is a precursor to tetraselenafulvalenes,^[4] the selenium analogue of tetrathiafulvalene, which can be further used to synthesize organic conductors and organic superconductors.

Carbon diselenide reacts with secondary amines to give :^[1]

Safety

Carbon diselenide has high vapor pressure. It has a moderate toxicity and presents an inhalation hazard. It may be dangerous due to its easy membrane transport. It decomposes slowly in storage (about 1% per month at –30 °C). When obtained commercially, its cost is high.^[5]

Pure distilled carbon diselenide has an odor very similar to that of carbon disulfide, but mixed with air, it creates extremely offensive odors (corresponding to new, highly toxic reaction products).^{[6] [7]} Its smell forced an evacuation of a nearby village when it was first synthesized in 1936.^[7] Because of the odor, synthetic pathways have been developed to avoid its use.^[8]

Notes and References

1. Book: John P. Fackler Jr. . Fackler, J. P. Jr. . Pan, W.-H. . Fackler, J. P. Jr. . Anderson, D. M. . Henderson, S. G. D. . Stephenson, T. A. . 2. Diselenocarbamates from Carbon Diselenide . Inorganic Syntheses . 21 . 6–11 . 1982 . 10.1002/9780470132524.ch2 . 978-0-470-13252-4.
2. Über Darstellung und Eigenschaften des Selenkohlenstoffs . Berichte der Deutschen Chemischen Gesellschaft (A and B Series) . 69 . 6 . 1936 . 1356–1364 . Grimm, H. G. . Metzger, H. . 10.1002/cber.19360690626.
3. Carraher, C. E. Jr. . Pittman, C. U. Jr. . Poly(Carbon Disulfide), Poly(Carbon Diselenide), and Polythiocyanogen . Inorganic Polymers . 2005 . 21 . 10.1002/14356007.a14_241 . 3-527-30673-0.
4. Engler, E. M. . Patel, V. V. . Structure control in organic metals. Synthesis of tetraselenofulvalene and its charge transfer salt with tetracyano-p-quinodimethane . Journal of the American Chemical Society . 1974 . 96 . 23 . 7376–7378 . 10.1021/ja00810a042 . 4814748.
5. Web site: Carbon Diselenide CSe₂ . Cse2.com . 2012-04-04.
6. Book: carbon diselenide has by far the worst odor this author has experienced in his lifetime of working with selenium compounds . Wolfgang H. H. Gunther . Organic Selenium Compounds: Their Chemistry and Biology.
7. Web site: Lowe . Derek . https://web.archive.org/web/20150923230748/http://blogs.sciencemag.org/pipeline/archives/2005/03/03/things_i_wont_work_with_carbon_diselenide/ . 23 September 2015 . Things I Won't Work With: Carbon Diselenide . In the Pipeline . Science . 20 November 2015 . Derek Lowe (chemist) . 2005-03-03.
8. US . 4462938 . patent . Wudl, F. . AT&T Bell Laboratories . 1984-07-31 . Process for producing chalcogen containing compounds. .