1-Hexanol

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1-Hexanol
Skeletal formula of 1-hexanol Spacefill formula of 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
Specific
heat capacity
C
243.2 J K−1 mol−1
Std molar
entropy
So298
287.4 J K−1 mol−1
Std enthalpy of
formation
ΔfHo298
−377.5 kJ mol−1
Std enthalpy of
combustion
ΔcHo298
−3.98437 MJ mol−1
Hazards
MSDS ICSC 1084
GHS pictograms The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word WARNING
GHS hazard statements H302
EU Index 603-059-00-6
EU classification Harmful Xn
R-phrases R22
S-phrases (S2), S24/25
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 59 °C (138 °F; 332 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
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[edit]

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[edit]

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):

Hexene-hexanol.png

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[edit]

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[edit]

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

References[edit]

  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. ^ a b 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[edit]