Bicyclopropenyl

Source: Wikipedia, the free encyclopedia.
Bicyclopropenyl
Names
Preferred IUPAC name
[1,1′-Bi(cyclopropane)]-1,1′-diene
Other names
1,1′-Bi(cycloprop-2-en-1-yl)
3,3'-Bicyclopropenyl
Identifiers
3D model (
JSmol
)
ChemSpider
  • InChI=1S/C6H6/c1-2-5(1)6-3-4-6/h1-6H ☒N
    Key: HVWGZGIZCKXHJV-UHFFFAOYSA-N ☒N
  • InChI=1/C6H6/c1-2-5(1)6-3-4-6/h1-6H
    Key: HVWGZGIZCKXHJV-UHFFFAOYAR
  • C\1=C\C/1C\2/C=C/2
Properties
C6H6
Molar mass 78.1 g/mol
Melting point −75 °C; −103 °F; 198 K
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Bicyclopropenyl (bicycloprop-2-enyl, C6H6) is an organic compound and one of several valence isomers of benzene. The molecule can be described as two coupled cyclopropene units. The positions of the alkene groups can vary and therefore two other isomers are known: bicycloprop-1,2-enyl and bicyclopropen-1-yl.

bicycloprop-2-enyl, bicycloprop-1-enyl and bicycloprop-1,2-enyl

The synthesis of all three isomers was reported in 1989 By Billups and Haley.

TBAF. In this latter reaction fluoride couples to the trimethylsilyl group, in the process forming the double bond and forcing the chlorine atom to leave as chloride. In presence of silver ions bicycloprop-2-enyl rearranges to Dewar benzene. The compound can also be trapped by cyclopentadiene. Above -10 °C it decomposes with polymerization
.

An

pm
).

The other two isomers are increasingly unstable. Bicycloprop-1-enyl can only be detected in trapping experiments.

Properties benzene valence isomers
Compound Calc.
Heat of formation[4][5]
 Calc. Heat of formation [4][5]
0 K (KJ/mole) 298 K (KJ/mole)
Benzene 100.5 82.0
Dewar benzene 415.5 397.1
Benzvalene 397.5 378.1
Prismane 567.2 547.0
Bicycloprop-2-enyl 593.6 578.8

Derivatives can be much more stable, for example perfluorohexamethylbicyclopropenyl that must be heated to 360 °C to be as unstable.[6]

References

  1. doi:10.1002/anie.198917111
    .
  2. doi:10.1016/S0040-4020(01)89261-9
    .
  3. doi:10.1021/ja00055a052
    .
  4. ^
    doi:10.1016/S0166-1280(98)00189-4
    .
  5. ^ a b G2 level, isodesmic bond separation scheme
  6. doi:10.1016/S0040-4020(01)89261-9
    .
Retrieved from "https://en.wikipedia.org/w/index.php?title=Bicyclopropenyl&oldid=1130115230"