Difference between revisions of "Cycloocta-1,5-diene"
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==Synthesis== | ==Synthesis== | ||
− | Cycloocta-1,5-diene can be prepared by dimerization of [[butadiene]] in the presence of a nickel catalyst, a coproduct being vinylcyclohexene. Approximately 10,000 tons were produced in 2005.<ref>{{ | + | Cycloocta-1,5-diene can be prepared by dimerization of [[butadiene]] in the presence of a nickel catalyst, a coproduct being vinylcyclohexene. Approximately 10,000 tons were produced in 2005.<ref>{{Ullmann | first1 = Thomas | last1 = Schiffer | first2 = Georg | last2 = Oenbrink | contribution = Cyclododecatriene, Cyclooctadiene, and 4-Vinylcyclohexene}}.</ref> |
==Organic reactions== | ==Organic reactions== |
Revision as of 09:58, 24 August 2009
1,5-Cyclooctadiene | |
---|---|
Identifiers | |
InChI | InChI=1/C8H12/c1-2-4-6-8-7-5-3-1/h1-2,7-8H,3-6H2/b2-1-,8-7- |
InChIKey | VYXHVRARDIDEHS-QGTKBVGQBM |
Standard InChI | InChI=1S/C8H12/c1-2-4-6-8-7-5-3-1/h1-2,7-8H,3-6H2/b2-1-,8-7- |
Standard InChIKey | VYXHVRARDIDEHS-QGTKBVGQSA-N |
CAS number | [ ] |
EC number | |
ChemSpider | |
Properties[1][2][3] | |
Chemical formula | C8H12 |
Molar mass | 108.18 g/mol |
Appearance | colorless liquid |
Density | 0.8818 g/ml, liquid (25 ºC) |
Melting point |
-69.35 ºC[note 1] |
Boiling point |
151 °C |
Solubility in water | 0.00641 g/100 ml (25 ºC, est.) |
Solubility | soluble in benzene |
log P | 3.16 |
Vapor pressure | 650 Pa (25 ºC) |
Refractive index (nD) | 1.4905 |
Hazards[2][4] | |
EU index number | not listed |
GHS pictograms | ![]() ![]() ![]() |
GHS signal word | WARNING |
GHS hazard statements | H226, H315, H319, H317, H400 |
GHS precautionary statements | P210, P233, P240, P241, P242, P243, P261, P264, P272, P273, P280, P302+352, P303+361+353, P305+351+338 |
Flash point | 35 ºC (95 ºF) |
Autoignition temp. | 207 ºC (431 ºF) |
Explosive limits | 1.0–8.6% (est.) |
Related compounds | |
Other compounds | Cyclooctene |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
Cycloocta-1,5-diene is the organic compound with the chemical formula C8H12. Generally abbreviated COD, this diene is a useful precursor to other organic compounds and serves as a ligand in organometallic chemistry.[5][6]
Contents
Synthesis
Cycloocta-1,5-diene can be prepared by dimerization of butadiene in the presence of a nickel catalyst, a coproduct being vinylcyclohexene. Approximately 10,000 tons were produced in 2005.[7]
Organic reactions
COD reacts with borane to give 9-borabicyclo[3.3.1]nonane, commonly known as 9-BBN, a reagent in organic chemistry used in hydroborations. COD adds SCl2 (or similar reagents) to give 2,6-dichloro-9-thiabicyclo[3.3.1]nonane:[8]
The resulting dichloride can be further modified as the di-azide or di-cyano derivative in a nucleophilic substitution aided by anchimeric assistance.
Metal complexes
Extensive work has been reported on complexes of COD, much of which can has been described in volumes 25, 26, and 28 of Inorganic Syntheses. COD typically binds to low-valence metals via both alkene groups. Metal-COD complexes are attractive because they are sufficiently stable to be isolated, often being more robust than related ethylene complexes. The stability of COD complexes is attributable to the chelate effect, but the COD ligands are easily displaced by other ligands, such as phosphines. In chemical formulae, when cyclooctadiene is acting as a ligand, it is conventional to write the abbreviation in lowercase, eg [Ni(cod)2].[9]
The complex Ni(cod)2 is a precursor to several nickel(0) and Ni(II) complexes. Ni(cod)2 is prepared by reduction of anhydrous nickel acetylacetonate in the presence of the ligand, using triethylaluminium.[10]
- 1/3[Ni(C5H7O2)2]3 + 2COD + 2Al(C2H5)3 → Ni(cod)2 + 2Al(C2H5)2(C5H7O2) + C2H4 + C2H6
The related Pt(cod)2 is prepared by a more circuitous route involving the dilithium cyclooctatetraene:[11]
- Li2C8H8 + PtCl2(cod) + 3C7H10 → [Pt(C7H10)3] + 2LiCl + C8H8 + C8H12
- Pt(C7H10)3 + 2COD → Pt(cod)2 + 3C7H10
The platinum complex has been used in many syntheses:
- Pt(cod)2 + 3 C2H4 → Pt(C2H4)3 + 2COD
COD complexes are useful as starting materials, one noteworthy example is the reaction:
- Ni(cod)2 + 4CO ⇌ Ni(CO)4 + 2COD
The product Ni(CO)4 is highly toxic, thus it is advantageous to generate it in the reaction vessel as opposed to being dispensed directly. Other low-valent metal complexes of COD include Mo(cod)(CO)4, [RuCl2(cod)]n, and Fe(cod)(CO)3. COD is an especially important in the coordination chemistry of rhodium(I) and iridium(I), examples being Crabtree's catalyst and cyclooctadiene rhodium chloride dimer. The square planar complexes [M(cod)2]+ are known (M = Rh, Ir).
Footnotes
- ↑ There is disagreement between sources as to the melting point of cycloocta-1,5-diene: Weast (1981) gives -70 ºC, while CHRIP (quoting a later edition of the CRC Handbook) gives -56.4 ºC. This value is from Ott et al. (1974), with an measurement uncertainty (estimated by the Thermodynamics Research Center, NIST Boulder Laboratories) of 0.06 K.
References
- ↑ CRC Handbook of Chemistry and Physics, 62nd ed.; Weast, Robert C., Ed.; CRC Press: Boca Raton, FL, 1981; p C-255. ISBN 0-8493-0462-8.
- ↑ 2.0 2.1 Chemical Risk Information Platform (CHRIP), <http://www.safe.nite.go.jp/english/db.html> (accessed 24 August 2009), National Institute of Technology and Evaluation (Japan).
- ↑ Ott, J. Bevan; Goates, J. Rex; Reeder, Joan Solid + liquid phase equilibria and solid-compound formation in hexafluorobenzene + cyclic hydrocarbons containing one or two pi-bonds. J. Chem. Thermodyn. 1974, 6 (3), 281–85. DOI: 10.1016/0021-9614(74)90181-5.
- ↑ HSNO Chemical Classification Information Database, <http://www.ermanz.govt.nz/Chemicals/ChemicalDisplay.aspx?SubstanceID=1536> (accessed 24 August 2009), New Zealand Environmental Risk Management Authority.
- ↑ Buehler, C.; Pearson, D. Survey of Organic Syntheses; Wiley-Interscience: New York, 1970.
- ↑ Shriver, Deward F.; Atkins, Peter W. Inorganic Chemistry; W. H. Freeman: New York, 1999.
- ↑ Schiffer, Thomas; Oenbrink, Georg Cyclododecatriene, Cyclooctadiene, and 4-Vinylcyclohexene. In Ullmann’s Encyclopedia of Industrial Chemistry, 5th ed.; Wiley-VCH: Weinheim, 2005.
- ↑ Bishop, Roger 9-Thiabicyclo[3.3.1]nonane-2,6-dione. Org. Synth. 1992, 70, 120, <http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV9P0692>; Coll. Vol., 9, 692. Díaz, David D.; Converso, Antonella; Sharpless, K. B.; Finn, M. G. 2,6-Dichloro-9-thiabicyclo[3.3.1]nonane: Multigram Display of Azide and Cyanide Components on a Versatile Scaffold. Molecules 2006, 11, 212–18. DOI: 10.3390/11040212.
- ↑ Rule IR-4.4.4 and Table VII. In Nomenclature of Inorganic Chemistry; IUPAC Recommendations 2005; Royal Society of Chemistry: Cambridge, 2005; pp 63, 261–68. ISBN 0-85404-438-8, <http://www.iupac.org/publications/books/rbook/Red_Book_2005.pdf>.
- ↑ Schunn, R. A.; Ittel, S. D.; Cushing, M. A.; Baker, R.; Gilbert, R. J.; Madden, D. P. Bis(1,5-Cyclooctadiene)Nickel(0). Inorg. Synth. 1990, 28, 94. DOI: 10.1002/9780470132593.ch25.
- ↑ Crascall, Louise E.; Spencer, John L.; Doyle, Ruth Ann; Angelici, Robert J. Olefin Complexes of Platinum. Inorg. Synth. 1990, 28, 126. DOI: 10.1002/9780470132593.ch34.
External links
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