1,5-Cyclooctadiene

Last updated
1,5-Cyclooctadiene
1,5-Cyclooctadiene.svg
1,5-cyclooctadiene-ED-3D-balls.png
Names
Preferred IUPAC name
Cycloocta-1,5-diene [1]
Identifiers
3D model (JSmol)
Abbreviations1,5-COD
2036542

1209288 (Z,Z)

ChemSpider
ECHA InfoCard 100.003.552 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 203-907-1
MeSH 1,5-cyclooctadiene
PubChem CID
RTECS number
  • GX9560000
    GX9620000 (Z,Z)
UNII
UN number 2520
  • InChI=1S/C8H12/c1-2-4-6-8-7-5-3-1/h1-2,7-8H,3-6H2/b2-1-,8-7- Yes check.svgY
    Key: VYXHVRARDIDEHS-QGTKBVGQSA-N Yes check.svgY
  • InChI=1/C8H12/c1-2-4-6-8-7-5-3-1/h1-2,7-8H,3-6H2/b2-1-,8-7-
    Key: VYXHVRARDIDEHS-QGTKBVGQBM
  • C1CC=CCCC=C1
Properties
C8H12
Molar mass 108.184 g·mol−1
AppearanceColorless liquid
Density 0.882 g/mL
Melting point −69 °C; −92 °F; 204 K
Boiling point 150 °C; 302 °F; 423 K
Vapor pressure 910 Pa
1.493
Thermochemistry
198.9 J K−1 mol−1
Std molar
entropy (S⦵298)
250.0 J K−1 mol−1
21–27 kJ mol−1
−4.890 – −4.884 MJ mol−1
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-silhouette.svg
Danger
H226, H304, H315, H317, H319, H334
P261, P280, P301+P310, P305+P351+P338, P331, P342+P311
Flash point 32 to 38 °C (90 to 100 °F; 305 to 311 K)
222 °C (432 °F; 495 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

1,5-Cyclooctadiene (also known as cycloocta-1,5-diene) is a cyclic hydrocarbon with the chemical formula C8H12, specifically [−(CH2)2−CH=CH−]2.

Contents

There are three configurational isomers with this structure, that differ by the arrangement of the four C–C single bonds adjacent to the double bonds. Each pair of single bonds can be on the same side (cis,Z) or on opposite sides (trans,E) of the double bond's plane; the three possibilities are denoted cis,cis, trans,trans, and cis,trans; or (Z,Z), (E,E), and (Z,E). (Because of overall symmetry, trans,cis is the same configuration as cis,trans.)

Generally abbreviated COD, the cis,cis isomer of this diene is a useful precursor to other organic compounds and serves as a ligand in organometallic chemistry. It is a colorless liquid with a strong odor. [2] [3] 1,5-Cyclooctadiene 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. [4] [5]

Organic reactions

COD reacts with borane to give 9-borabicyclo[3.3.1]nonane, [6] commonly known as 9-BBN, a reagent in organic chemistry used in hydroborations:

Synthesis of 9-BBN dimer.png

COD adds SCl2 (or similar reagents) to give 2,6-dichloro-9-thiabicyclo[3.3.1]nonane: [7] [8]

CODSCl2.png

The resulting dichloride can be further modified as the diazide or dicyano derivative in a nucleophilic substitution aided by anchimeric assistance.

COD is used as an intermediate in one of the syntheses of disparlure, a gypsy moth pheromone. [9]

Metal complexes

1,5-COD binds to low-valent 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. The COD ligands are easily displaced by other ligands, such as phosphines.

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

Extensive work has been reported on complexes of COD, much of which has been described in volumes 25, 26, and 28 of Inorganic Syntheses . The platinum complex is a precursor to a 16-electron complex of ethylene:

Pt(COD)2 + 3C2H4 → 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 upon demand. Other low-valent metal complexes of COD include cyclooctadiene rhodium chloride dimer, cyclooctadiene iridium chloride dimer, and Fe(COD)(CO)3, and Crabtree's catalyst.

The M(COD)2 complexes with nickel, palladium, and platinum have tetrahedral geometry, whereas [M(COD)2]+ complexes of rhodium and iridium are square planar.

(E,E)-COD

E,E-COD synthesis (Stockmann et al. 2011) EE-COD synthesis.svg
E,E-COD synthesis (Stöckmann et al. 2011)

The highly strained trans,trans isomer of 1,5-cyclooctadiene is a known compound. (E,E)-COD was first synthesized by George M. Whitesides and Arthur C. Cope in 1969 by photoisomerization of the cis,cis compound. [12] Another synthesis (double elimination reaction from a cyclooctane ring) was reported by Rolf Huisgen in 1987. [13] The molecular conformation of (E,E)-COD is twisted rather than chair-like. The compound has been investigated as a click chemistry mediator. [14]

Related Research Articles

<span class="mw-page-title-main">Diene</span> Covalent compound that contains two double bonds

In organic chemistry, a diene ; also diolefin, dy-OH-lə-fin) or alkadiene) is a covalent compound that contains two double bonds, usually among carbon atoms. They thus contain two alkene units, with the standard prefix di of systematic nomenclature. As a subunit of more complex molecules, dienes occur in naturally occurring and synthetic chemicals and are used in organic synthesis. Conjugated dienes are widely used as monomers in the polymer industry. Polyunsaturated fats are of interest to nutrition.

<span class="mw-page-title-main">Nickel(II) chloride</span> Chemical compound

Nickel(II) chloride (or just nickel chloride) is the chemical compound NiCl2. The anhydrous salt is yellow, but the more familiar hydrate NiCl2·6H2O is green. Nickel(II) chloride, in various forms, is the most important source of nickel for chemical synthesis. The nickel chlorides are deliquescent, absorbing moisture from the air to form a solution. Nickel salts have been shown to be carcinogenic to the lungs and nasal passages in cases of long-term inhalation exposure.

Organopalladium chemistry is a branch of organometallic chemistry that deals with organic palladium compounds and their reactions. Palladium is often used as a catalyst in the reduction of alkenes and alkynes with hydrogen. This process involves the formation of a palladium-carbon covalent bond. Palladium is also prominent in carbon-carbon coupling reactions, as demonstrated in tandem reactions.

<span class="mw-page-title-main">Rhodium(III) chloride</span> Chemical compound

Rhodium(III) chloride refers to inorganic compounds with the formula RhCl3(H2O)n, where n varies from 0 to 3. These are diamagnetic red-brown solids. The soluble trihydrated (n = 3) salt is the usual compound of commerce. It is widely used to prepare compounds used in homogeneous catalysis.

<span class="mw-page-title-main">Sulfur dichloride</span> Chemical compound

Sulfur dichloride is the chemical compound with the formula SCl2. This cherry-red liquid is the simplest sulfur chloride and one of the most common, and it is used as a precursor to organosulfur compounds. It is a highly corrosive and toxic substance, and it reacts on contact with water to form chlorine-containing acids.

<span class="mw-page-title-main">Crabtree's catalyst</span> Chemical compound

Crabtree's catalyst is an organoiridium compound with the formula [C8H12IrP(C6H11)3C5H5N]PF6. It is a homogeneous catalyst for hydrogenation and hydrogen-transfer reactions, developed by Robert H. Crabtree. This air stable orange solid is commercially available and known for its directed hydrogenation to give trans stereoselectivity with respective of directing group.

<span class="mw-page-title-main">Platinum(II) chloride</span> Chemical compound

Platinum(II) chloride is the chemical compound PtCl2. It is an important precursor used in the preparation of other platinum compounds. It exists in two crystalline forms, but the main properties are somewhat similar: dark brown, insoluble in water, diamagnetic, and odorless.

<span class="mw-page-title-main">Cyclooctadiene rhodium chloride dimer</span> Chemical compound

Cyclooctadiene rhodium chloride dimer is the organorhodium compound with the formula Rh2Cl2(C8H12)2, commonly abbreviated [RhCl(COD)]2 or Rh2Cl2(COD)2. This yellow-orange, air-stable compound is a widely used precursor to homogeneous catalysts.

Martin Arthur Bennett FRS is an Australian inorganic chemist. He gained recognition for studies on the co-ordination chemistry of tertiary phosphines, olefins, and acetylenes, and the relationship of their behaviour to homogeneous catalysis.

<span class="mw-page-title-main">Triphenyl phosphite</span> Chemical compound

Triphenyl phosphite is the organophosphorus compound with the formula P(OC6H5)3. It is a colourless viscous liquid.

<span class="mw-page-title-main">Bis(cyclooctadiene)nickel(0)</span> Chemical compound

Bis(cyclooctadiene)nickel(0) is the organonickel compound with the formula Ni(C8H12)2, also written Ni(cod)2. It is a diamagnetic coordination complex featuring tetrahedral nickel(0) bound to the alkene groups in two 1,5-cyclooctadiene ligands. This highly air-sensitive yellow solid is a common source of Ni(0) in chemical synthesis.

<span class="mw-page-title-main">Organoiridium chemistry</span> Chemistry of organometallic compounds containing an iridium-carbon bond

Organoiridium chemistry is the chemistry of organometallic compounds containing an iridium-carbon chemical bond. Organoiridium compounds are relevant to many important processes including olefin hydrogenation and the industrial synthesis of acetic acid. They are also of great academic interest because of the diversity of the reactions and their relevance to the synthesis of fine chemicals.

<span class="mw-page-title-main">Dichloro(cycloocta-1,5-diene)platinum(II)</span> Chemical compound

Dichloro(1,5-cyclooctadiene)platinum(II) (Pt(cod)Cl2) is an organometallic compound of platinum. This colourless solid is an entry point to other platinum compounds through the displacement of the cod and/or chloride ligands. It is one of several complexes of cycloocta-1,5-diene.

Organoplatinum chemistry is the chemistry of organometallic compounds containing a carbon to platinum chemical bond, and the study of platinum as a catalyst in organic reactions. Organoplatinum compounds exist in oxidation state 0 to IV, with oxidation state II most abundant. The general order in bond strength is Pt-C (sp) > Pt-O > Pt-N > Pt-C (sp3). Organoplatinum and organopalladium chemistry are similar, but organoplatinum compounds are more stable and therefore less useful as catalysts.

Metal acetylacetonates are coordination complexes derived from the acetylacetonate anion (CH
3COCHCOCH−
3) and metal ions, usually transition metals. The bidentate ligand acetylacetonate is often abbreviated acac. Typically both oxygen atoms bind to the metal to form a six-membered chelate ring. The simplest complexes have the formula M(acac)3 and M(acac)2. Mixed-ligand complexes, e.g. VO(acac)2, are also numerous. Variations of acetylacetonate have also been developed with myriad substituents in place of methyl (RCOCHCOR′−). Many such complexes are soluble in organic solvents, in contrast to the related metal halides. Because of these properties, acac complexes are sometimes used as catalyst precursors and reagents. Applications include their use as NMR "shift reagents" and as catalysts for organic synthesis, and precursors to industrial hydroformylation catalysts. C
5H
7O−
2 in some cases also binds to metals through the central carbon atom; this bonding mode is more common for the third-row transition metals such as platinum(II) and iridium(III).

<span class="mw-page-title-main">Metal halides</span>

Metal halides are compounds between metals and halogens. Some, such as sodium chloride are ionic, while others are covalently bonded. A few metal halides are discrete molecules, such as uranium hexafluoride, but most adopt polymeric structures, such as palladium chloride.

<span class="mw-page-title-main">Cyclooctadiene iridium chloride dimer</span> Chemical compound

Cyclooctadiene iridium chloride dimer is an organoiridium compound with the formula [Ir(μ2-Cl)(COD)]2, where COD is the diene 1,5-cyclooctadiene (C8H12). It is an orange-red solid that is soluble in organic solvents. The complex is used as a precursor to other iridium complexes, some of which are used in homogeneous catalysis. The solid is air-stable but its solutions degrade in air.

<span class="mw-page-title-main">Chlorobis(cyclooctene)rhodium dimer</span> Chemical compound

Chlorobis(cyclooctene)rhodium dimer is an organorhodium compound with the formula Rh2Cl2(C8H14)4, where C8H14 is cis-cyclooctene. Sometimes abbreviated Rh2Cl2(coe)4, it is a red-brown, air-sensitive solid that is a precursor to many other organorhodium compounds and catalysts.

<span class="mw-page-title-main">Chlorobis(cyclooctene)iridium dimer</span> Chemical compound

Chlorobis(cyclooctene)iridium dimer is an organoiridium compound with the formula Ir2Cl2(C8H14)4, where C8H14 is cis-cyclooctene. Sometimes abbreviated Ir2Cl2(coe)4, it is a yellow, air-sensitive solid that is used as a precursor to many other organoiridium compounds and catalysts.

<span class="mw-page-title-main">Cyclooctadiene iridium methoxide dimer</span> Chemical compound

Cyclooctadiene iridium methoxide dimer is an organoiridium compound with the formula Ir2(OCH3)2(C8H12)2, where C8H12 is the diene 1,5-cyclooctadiene. It is a yellow solid that is soluble in organic solvents. The complex is used as a precursor to other iridium complexes, some of which are used in homogeneous catalysis.

References

  1. ↑ "AC1L1QCE - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification and Related Records. Retrieved 14 October 2011.
  2. ↑ Buehler, C.; Pearson, D. (1970). Survey of Organic Syntheses . New York: Wiley-Interscience.
  3. ↑ Shriver, D.; Atkins, P. (1999). Inorganic Chemistry . New York: W. H. Freeman and Co. ISBN   978-0-716-72873-3.
  4. ↑ Schiffer, Thomas; Oenbrink, Georg. "Cyclododecatriene, Cyclooctadiene, and 4-Vinylcyclohexene". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_205.pub2. ISBN   978-3527306732.
  5. ↑ Lee, H; Campbell, M. G.; Sánchez, R. H.; Börgel, J.; Raynaud, J; Parker, S. E.; Ritter, T. (2016). "Mechanistic Insight Into High-Spin Iron(I)-Catalyzed Butadiene Dimerization". Organometallics . 35 (17): 2923–2929. doi:10.1021/acs.organomet.6b00474.
  6. ↑ Soderquist, John A.; Negron, Alvin (1998). "9-Borabicyclo[3.3.1]nonane Dimer". Organic Syntheses ; Collected Volumes, vol. 9, p. 95.
  7. ↑ Bishop, Roger. "9-Thiabicyclo[3.3.1]nonane-2,6-dione". Organic Syntheses ; Collected Volumes, vol. 9, p. 692.
  8. ↑ Díaz, David; Converso, Antonella; Sharpless, K. Barry; Finn, M. G. (2006). "2,6-Dichloro-9-thiabicyclo[3.3.1]nonane: Multigram Display of Azide and Cyanide Components on a Versatile Scaffold" (PDF). Molecules . 11 (4): 212–218. doi: 10.3390/11040212 . PMC   6148556 . PMID   17962753. Open Access logo PLoS transparent.svg
  9. ↑ Klünenberg, Helmut; Schäfer, Hans J. (1978). "Synthesis of Disparlure by Kolbe Electrolysis". Angewandte Chemie International Edition in English. 17: 47–48. doi:10.1002/anie.197800471.
  10. ↑ Schunn, R.; Ittel, S. (2007). "Bis(1,5-Cyclooctadiene)Nickel(0)". Inorganic Syntheses. Vol. 28. pp. 94–98. doi:10.1002/9780470132593.ch25. ISBN   978-0-470-13259-3.
  11. ↑ Crascall, L; Spencer, J. (2007). "Olefin Complexes of Platinum". Inorganic Syntheses. Vol. 28. pp. 126–132. doi:10.1002/9780470132593.ch34. ISBN   978-0-470-13259-3.
  12. ↑ Whitesides, George M.; Goe, Gerald L.; Cope, Arthur C. (1969). "Irradiation of cis,cis-1,5-cyclooctadiene in the presence of copper(I) chloride". J. Am. Chem. Soc. 91 (10): 2608–2616. doi:10.1021/ja01038a036.
  13. ↑ Boeckh, Dieter; Huisgen, Rolf; Noeth, Heinrich (1987). "Preparation and conformation of (E,E)-1,5-cyclooctadiene". J. Am. Chem. Soc. 109 (4): 1248–1249. doi:10.1021/ja00238a046.
  14. ↑ Stöckmann, Henning; Neves, André A.; Day, Henry A.; Stairs, Shaun; Brindle, Kevin M.; Leeper, Finian J. (2011). "(E,E)-1,5-Cyclooctadiene: a small and fast click-chemistry multitalent". Chem. Commun. 47 (25): 7203–5. doi:10.1039/C1CC12161H. PMID   21611648.
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