1,5-cyclooctadiene

Structural formula
General
Surname	1,5-cyclooctadiene
other names	Cycloocta-1,5-diene COD
Molecular formula	C 8 H 12
Brief description	colorless liquid with an unpleasant odor
External identifiers / databases
CAS number 111-78-4 (unspec.) 1552-12-1 (Z, Z) isomer 5259-71-2 (Z, E) isomer 17612-50-9 (E, E) isomer EC number 203-907-1 ECHA InfoCard 100.003.552 PubChem 82916 Wikidata Q161547
properties
Molar mass	108.18 g mol −1
Physical state	liquid
density	0.88 g cm −3 (20 ° C)
Melting point	−70 ° C
boiling point	150 ° C
Vapor pressure	6.5 h Pa (20 ° C) 13 hPa (35 ° C)
solubility	very bad in water (<500 mg l −1 at 20 ° C)
Refractive index	1.4905
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 226-302 + 332-315-317-319 P: 280-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

1,5-Cyclooctadiene is an organic compound with the empirical formula C ₈ H ₁₂ . It consists of an eight-membered ring which is doubly unsaturated and, as a cyclic diene, belongs to the cycloalkenes . The double bonds are not conjugated . 1,5-Cyclooctadiene is abbreviated as COD , especially in complexes .

presentation

1,5-cyclooctadiene, by dimerization of 1,3-butadiene in the nickel catalyst- bis [cyclooctadiene (1.5)] - nickel (0) are prepared. The worldwide annual production is around 10,000 tons.

Connections and reactions

Structure of [M (COD) ₂ ] complexes

It can be used as a labile bidentate chelating ligand in transition metal complexes. Here, 1,5-cyclooctadiene binds via both double bonds to the metal center. COD can easily be substituted by other ligands , which is why COD complexes can be used as starting materials for complex synthesis.

${\displaystyle \mathrm {Ni(COD)_{2}\ +\ 4\ CO\leftrightharpoons \ Ni(CO)_{4}\ +\ 2\ COD} }$

Manufacture of nickel tetracarbonyl from Ni (COD) ₂ and carbon monoxide .

Ni (COD) ₂ can be prepared by reduction of nickel acetylacetonate with trimethylaluminum be prepared and COD.

${\displaystyle \mathrm {[Ni(C_{5}H_{7}O_{2})_{2}]_{3}\ +\ 6\ COD\ +\ 6\ Al(C_{2}H_{5})_{3}\rightarrow } }$

${\displaystyle \mathrm {3\ Ni(COD)_{2}\ +\ 6\ Al(C_{2}H_{5})_{2}(C_{5}H_{7}O_{2})\ +\ 3\ C_{2}H_{4}\ +\ 3\ C_{2}H_{6}} }$

A number of low-valent transition metal complexes with COD are known, of which the Crabtree catalyst is of greater importance .

9-BBN , which is used for hydroboration , is produced by adding COD to a monoborane adduct.

Web links

Commons : 1,5-Cyclooctadiene  - Collection of pictures, videos, and audio files

Individual evidence

1. ↑ ^{a b c d e f g h i} Entry on Cycloocta-1,5-diene in the GESTIS substance database of the IFA , accessed on September 29, 2019(JavaScript required) .
2. ↑ CRC Handbook of Tables for Organic Compound Identification , Third Edition, 1984, ISBN 0-8493-0303-6 .
3. ↑ Thomas Schiffer, Georg Oenbrink: Cyclododecatriene, Cyclooctadiene, and 4-Vinylcyclohexene , in: Ullmanns Enzyklopädie der Technischen Chemie , Wiley-VCH, Weinheim 2005.
4. ↑ R. Schunn, S. Ittel, Bis (1,5-Cyclooctadiene) Nickel (0) , in: Inorg. Synth. , 1990 , 28 , p. 94; doi : 10.1002 / 9780470132593.ch25 .
5. ↑ John A. Soderquist, Alvin Negron: 9-Borabicyclo [3.3.1] nonane, dimer In: Organic Syntheses . 70, 1992, p. 169, doi : 10.15227 / orgsyn.070.0169 ; Coll. Vol. 9, 1998, p. 95 ( PDF ).