Carbon diselenide

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Carbon Diselenide
Other names Carbon Selenide, Diselenoxomethane, Methanediselone
Identifiers
CAS number [506-80-9]
Properties
Molecular formula CSe2
Molar mass 169.93 g/mol
Appearance yellow liquid
Density 2.69
Melting point

-43.7°C

Boiling point

125.5°C

Solubility in water insoluble in water
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Carbon diselenide is a inorganic compound with the chemical formula CSe2. This yellowish liquid has a pungent odor. It is an analogue of CS2. Carbon diselenide polymerizes under high pressure.

[edit] Synthesis, structure and reactions

Carbon diselenide is a linear molecule with D∞h symmetry. Its is produced by reacting selenium powder with dichloromethane vapor under 550 °C.

2 Se + CH2Cl2 → CSe2 + 2 HCl

It was first synthesized by Grimm and Metzger by reacting hydrogen selenium with carbon tetrachloride in a hot tube.[1]

Like carbon disulfides, it polymerizes at high pressures. The structure of the polymer is thought to be a head-to-head structure with a backbone in the form of -[Se-C-C-Se]-.[2] The polymer is a semiconductor with a room-temperature conductivity of 50 S/cm.

In addition, carbon diselenide is used in the synthesis of tetraselenafulvalene[3], a selenium analogue of tetrathiafulvalene, which can be further used to synthesize organic conductors and superconductors.

Carbon diselenide reacts with secondary amines to give dialkydiselenocarbamates:[4]

2 Et2NH + CSe2 → Et2NH2+)(Et2NCSe2-)

[edit] References

  1. ^ H. G. Grimm, H. Metzger (1936). "Über Darstellung und Eigenschaften des Selenkohlenstoffs". Berichte der deutschen chemischen Gesellschaft (A and B Series) 69 (6): 1356–1364. doi:10.1002/cber.19360690626. 
  2. ^ C. E. Carraher, Jr. and C.U. Pittman, Jr. (2005). "Poly(Carbon Disulfide), Poly(Carbon Diselenide), and Polythiocyanogen". Inorganic Polymers 21. doi:10.1002/14356007.a14_241. 
  3. ^ Edward M. Engler, Vishnu V. Patel (1974). "Structure control in organic metals. Synthesis of tetraselenofulvalene and its charge transfer salt with tetracyano-p-quinodimethane". Journal of American Chemical Society 96 (23): 7376–7378. 
  4. ^ W. Pan and J. P. Fackler, Jr. (1982). "Diselenocarbamates from carbon diselenide". Inorganic Syntheses 21: 6. doi:10.1002/9780470132524.ch2.