Norbornadiene

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Norbornadiene
IUPAC name Bicyclo[2.2.1]hepta-2,5-diene
Other names 2,5-Norbornadiene
Identifiers
CAS number [121-46-0]
PubChem 8473
EINECS number 204-472-0
SMILES C1C2C=CC1C=C2
Properties
Molecular formula C7H8
Molar mass 92.14 g/mol
Density 0.906 g/cm³
Melting point

-19 °C, 254 K, -2 °F

Boiling point

89 °C, 362 K, 192 °F

Solubility in water Insoluble
Hazards
R-phrases R11
S-phrases S9 S16 S29 S33
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Norbornadiene is a bicyclic hydrocarbon. The molecule can be envisioned as a 1,4-cyclohexadiene bridged in the para positions by a methylene group. The compound is related to norbornene in which one of the double bonds is saturated. Norbornadiene and related compounds are of great scientific interest because of the unusual geometry and high reactivity.

Contents

[edit] Synthesis

The norbornadiene framework is based on a Diels-Alder reaction between a cyclopentadiene and an alkyne.

Norbornadiene synthesis

[edit] Reactions

Quadricyclane is a highly toxic4 norbornadiene isomer. It can be obtained from norbornadiene by a photochemical reaction when assisted by a sensitizer such as acetophenone. The norbornadiene quadricyclane couple is of potential interest for solar energy storage when controlled release of the strain energy stored in quadricyclane back to norbornadiene is made possible.1 Quadricyclane is very reactive towards dienophiles in cycloaddition reactions.

quadricyclane

Norbornadienes also form organometallic complexes, where it can act as a two-electron or four-electron donor. Sandwich compounds such as tetracarbonyl(norbornadiene)chromium(0),3 which is a useful reagent for transferring chromium tetracarbonyl to bidentate phosphine ligands, are known.

Norbornadiene is also the starting material for the synthesis of diamantane and sumanene and it is used as an acetylene transfer agent for instance in reaction with 3,6-di-2-pyridyl-1,2,4,5-tetrazine.2

[edit] References

  • 1 Rh(III)-Photosensitized Interconversion of Norbornadiene and Quadricyclane Gregory W. Sluggett, Nicholas J. Turro, and Heinz D. Roth, J. Phys. Chem. A 1997, 101, 8834-8838
  • 2 π-Bond Screening in Benzonorbornadienes: The Role of 7-Substituents in Governing the Facial Selectivity for the Diels-Alder Reaction of Benzonorbornadienes with 3,6-Di(2-pyridyl)-s-Tetrazine. Ronald N. Warrener and Peter A. Harrison Molecules 2001, 6, 353–369 Online Article
  • 3 High yield synthesis and structures of some achiral and chiral (diphosphine)tetracarbonylchromium(0) chelate complexes with tetracarbonyl(norbornadiene)chromium(0) as complexation reagent Markus Strotmann, Rudolf Wartchow, and Holger Butenschön Arkivoc KK-1112F 2004 Online Article
  • 4 http://www.stormingmedia.us/07/0755/A075523.html

[edit] External links