1-Hexanol

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1-Hexanol
Identifiers
CAS number 111-27-3 YesY
PubChem 8103
ChemSpider 7812 YesY
UNII 6CP2QER8GS YesY
EC number 203-852-3
UN number 2282
MeSH 1-Hexanol
ChEMBL CHEMBL14085 YesY
RTECS number MQ4025000
Beilstein Reference 969167
Jmol-3D images Image 1
Properties
Molecular formula C6H14O
Molar mass 102.17 g mol−1
Density .8136 g cm−3
Melting point −53 to −41 °C; −64 to −42 °F; 220 to 232 K
Boiling point 155 to 159 °C; 311 to 318 °F; 428 to 432 K
Solubility in water 5.9 g/L (at 20 ºC)
log P 1.858
Vapor pressure 100 Pa (at 25.6 ºC)
Refractive index (nD) 1.4178 (at 20 ºC)
Thermochemistry
Std enthalpy of
formation
ΔfHo298
−377.5 kJ mol−1
Std enthalpy of
combustion
ΔcHo298
−3.98437 MJ mol−1
Standard molar
entropy
So298
287.4 J K−1 mol−1
Specific heat capacity, C 243.2 J K−1 mol−1
Hazards
MSDS ICSC 1084
GHS pictograms
GHS signal word WARNING
GHS hazard statements H302
EU Index 603-059-00-6
EU classification Xn
R-phrases R22
S-phrases (S2), S24/25
NFPA 704
2
1
0
Flash point 59 °C; 138 °F; 332 K
Autoignition temperature 293 °C; 559 °F; 566 K
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

1-Hexanol is an organic alcohol with a six-carbon chain and a condensed structural formula of CH3(CH2)5OH. This colorless liquid is slightly soluble in water, but miscible with ether and ethanol. Two additional straight chain isomers of 1-hexanol, 2-hexanol and 3-hexanol, exist, both of which differing by the location of the hydroxyl group. Many isomeric alcohols have the formula C6H13OH. It is used in the perfume industry.

Preparation

Hexanol is produced industrially by the oligomerization of ethylene using triethylaluminium followed by oxidation of the alkylaluminium products.[2] An idealized synthesis is shown:

Al(C2H5)3 + 6C2H4 → Al(C6H13)3
Al(C6H13)3 + 1½O2 + 3H2O → 3HOC6H13 + Al(OH)3

The process generates a range of oligomers that are separated by distillation.

Alternative methods

Another method of preparation entails hydroformylation of 1-pentene followed by hydrogenation of the resulting aldehydes. This method is practiced in industry to produce mixtures of isomeric C6-alcohols, which are precursors to plasticizers.[2]

In principle, 1-hexene could be converted to 1-hexanol by hydroboration (diborane in tetrahydrofuran followed by treatment with hydrogen peroxide and sodium hydroxide):

This method is instructive and useful in laboratory synthesis but of no practical relevance because of the commercial availability of inexpensive 1-hexanol from ethylene.

Occurrence in Nature

1-Hexanol is believed to be a component of the odour of freshly mown grass. Alarm pheromones emitted by the Koschevnikov gland of honey bees contain 1-hexanol.

See also

Cis-3-Hexenal, another volatile organic carbon biomolecule, is also considered responsible for the freshly mowed grass flavor.

References

  1. "1-hexanol - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification and Related Records. Retrieved 8 October 2011. 
  2. 2.0 2.1 Falbe, Jürgen; Bahrmann, Helmut; Lipps, Wolfgang; Mayer, Dieter (2005), "Alcohols, Aliphatic", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a01_279 .

External links

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