1-Octene

1-Octene
IUPAC name Oct-1-ene
Other names Octene-1, octylene; 1-n-ctene; hexylethylene; oct-1-ene; octene
Identifiers
CAS number	111-66-0 Y
PubChem	8125
ChemSpider	7833 Y
ChEBI	CHEBI:46708 Y
Jmol-3D images	Image 1
SMILES C=CCCCCCC
InChI InChI=1S/C8H16/c1-3-5-7-8-6-4-2/h3H,1,4-8H2,2H3 Y Key: KWKAKUADMBZCLK-UHFFFAOYSA-N Y InChI=1/C8H16/c1-3-5-7-8-6-4-2/h3H,1,4-8H2,2H3 Key: KWKAKUADMBZCLK-UHFFFAOYAN
Properties
Molecular formula	C8H16
Molar mass	112.24 g/mol
Density	0.715 g/cm³
Melting point	-101.7 °C [1]
Boiling point	121 °C [2]
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

1-Octene is an organic compound with a formula CH₂CHC₆H₁₃. The alkene is classified as a higher olefin and alpha-olefin, meaning that the double bond is located at the alpha (primary) position, endowing this compound with higher reactivity and thus useful chemical properties. 1-Octene is one of the important linear alpha olefins in industry. It is a colourless liquid.

Synthesis

In industry, 1-octene is commonly manufactured by two main routes: oligomerization of ethylene and by Fischer-Tropsch synthesis followed by purification. Another route to 1-octene that has been used commercially on a small scale is dehydration of alcohols. Prior to the 1970s, 1-octene was also manufactured by thermal cracking of waxes, whereas linear internal octenes were also manufactured by chlorination/dehydrochlorination of linear paraffins.

There are five commercial processes that oligomerize ethylene to 1-octene. Four of these processes produce 1-octene as a part of a wide distribution of alpha-olefins. In typical circumstances, 1-hexene content of the entire distribution of alpha-olefins ranges from about 25% of the distribution in the Ethyl (Innovene) process to about 8% of distribution in some modes of the Gulf (CP Chemicals) and Idemitsu processes.

The only commercial process to isolate 1-octene from a wide mixture of C₈ hydrocarbons is practiced by Sasol, a South African oil and gas and petrochemical company. For commercial purposes, Sasol employs Fischer-Tropsch synthesis to make fuels from synthesis gas derived from coal and recovers 1-octene from these fuel streams, where the initial 1-octene concentration in a narrow distillation cut may be 60%, with the remainder being vinylidenes, linear and branched internal olefins, linear and branched paraffins, alcohols, aldehydes, carboxylic acids, and aromatic compounds.

In recent years, two on-purpose 1-octene technologies have been commercialised: a butadiene telomerisation plant (Dow, Tarragona), and a 1-heptene to 1-octene plant based on a Fischer-Tropsch-derived C₇ olefin stream (Sasol, Secunda). Sasol is currently in the engineering phase of a new 1-octene technology based on selective tetramerisation of ethylene.^[3]

Applications

The main use of 1-octene is as a comonomer in production of polyethylene. High-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) use approximately 2–4% and 8–10% of comonomers, respectively.

Another significant use of 1-octene is for production of linear aldehyde via the oxo synthesis (hydroformylation) to give the C9 aldehyde (nonanal). Oxidation of this aldehyde gives the short-chain fatty acid nonanoic acid. Hydrogenation of the same aldehyde gives the [[fatty alcohol] 1-nonanol, which is used as a plasticizer.

References

1. ^ http://webbook.nist.gov/cgi/cbook.cgi?ID=C111660&Units=SI&Mask=1EFF
2. ^ http://webbook.nist.gov/cgi/cbook.cgi?ID=C111660&Units=SI&Mask=1EFF
3. ^ Annette Bollmann, Kevin Blann, John T. Dixon, Fiona M. Hess, Esna Killian, Hulisani Maumela, David S. McGuinness, David H. Morgan, Arno Neveling, Stefanus Otto, Matthew Overett, Alexandra M. Z. Slawin, Peter Wasserscheid, and Sven Kuhlmann "Ethylene Tetramerization:  A New Route to Produce 1-Octene in Exceptionally High Selectivities" J. Am. Chem. Soc., 2004, 126 (45), pp 14712–14713. doi:10.1021/ja045602n