1,5-Cyclooctadiene

1,5-Cyclooctadiene

Names
Systematic IUPAC name Cycloocta-1,5-diene
Identifiers
CAS Number	111-78-4 Y 1552-12-1 (Z,Z) Y 5259-71-2 (Z,E) Y 17612-50-9 (E,E) Y
3D model (Jmol)	Interactive image
Abbreviations	1,5-COD
Beilstein Reference	2036542 1209288 (Z,Z)
ChemSpider	7843 N 74815 (Z,Z) Y 18520443 (Z,E) Y 19971660 (E,E) Y
ECHA InfoCard	100.003.552
EC Number	203-907-1
MeSH	1,5-cyclooctadiene
PubChem CID	8135 82916 (Z,Z) 5364364 (Z,E) 5702534 (E,E)
RTECS number	GX9560000 GX9620000 (Z,Z)
UN number	2520
InChI InChI=1S/C8H12/c1-2-4-6-8-7-5-3-1/h1-2,7-8H,3-6H2/b2-1-,8-7- Y Key: VYXHVRARDIDEHS-QGTKBVGQSA-N Y 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
SMILES C1CC=CCCC=C1
Properties
Chemical formula	C8H12
Molar mass	108.18 g·mol−1
Appearance	Colorless 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
Refractive index (nD)	1.493
Thermochemistry
Specific heat capacity (C)	198.9 J K−1 mol−1
Std molar entropy (So298)	250.0 J K−1 mol−1
Std enthalpy of formation (ΔfHo298)	21–27 kJ mol−1
Std enthalpy of combustion (ΔcHo298)	−4.890 – −4.884 MJ mol−1
Hazards
GHS pictograms
GHS signal word	DANGER
GHS hazard statements	H226, H304, H315, H317, H319, H334
GHS precautionary statements	P261, P280, P301+310, P305+351+338, P331, P342+311
Flash point	32 to 38 °C (90 to 100 °F; 305 to 311 K)
Autoignition temperature	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).
N  (what is YN ?)
Infobox references

1209288 (Z,Z)

GX9620000 (Z,Z)

1,5-Cyclooctadiene 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. It is a colorless liquid with a strong odor. 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.

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:

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

Bis(cyclooctadiene)nickel(0).

Crabtree's catalyst.

The complex Rh₂(COD)₂Cl₂.

Co(1,5-cyclooctadiene)(cyclooctenyl).

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