Heneicosane

Heneicosane is the organic compound with the formula CH₃(CH₂)₁₉CH₃. It is the straight chain, saturated C21 hydrocarbon. It is a white wax.

Heneicosane

Names
Preferred IUPAC name Henicosane
Other names n-Heneicosane
Identifiers
CAS Number	629-94-7 Y
3D model (JSmol)	Interactive image
Beilstein Reference	1748500
ChEBI	CHEBI:32931 Y
ChemSpider	11897 Y
ECHA InfoCard	100.010.109
EC Number	211-118-9
PubChem CID	12403
UNII	I93S5U5DMP Y
CompTox Dashboard (EPA)	DTXSID9047097
InChI InChI=1S/C21H44/c1-3-5-7-9-11-13-15-17-19-21-20-18-16-14-12-10-8-6-4-2/h3-21H2,1-2H3 Y Key: FNAZRRHPUDJQCJ-UHFFFAOYSA-N Y
SMILES CCCCCCCCCCCCCCCCCCCCC
Properties
Chemical formula	C21H44
Molar mass	296.583 g·mol−1
Appearance	Waxy solid
Density	0.7919 g mL−1
Melting point	40.5 °C (104.9 °F; 313.6 K)
Boiling point	356.10 °C; 672.98 °F; 629.25 K
Solubility in water	2.9·10−11 g/L
log P	10.65
Vapor pressure	8.73·10−5 mm Hg
Henry's law constant (kH)	120 atm·m3/mole
Refractive index (nD)	1.4441
Hazards
NFPA 704 (fire diamond)	1 1 0
Flash point	113 °C (235 °F; 386 K)
Related compounds
Related alkanes	Icosane Tetracosane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Natural occurrence

Heneicosane is used as a pheromone by the queen or king termites in the species Reticulitermes flavipes.^[1] It also attracts mosquitoes in the genus Aedes and can be used in mosquito baits.^[2] This works in nature as the hydrocarbon is produced in the skin of the larva. A 1:100000 fraction in water is the most attractive, but if the concentration is 1:1000 then mosquitoes are repelled instead.^[3] Heneicosane is one of the major components of the safflower flower essential oil (Carthamus tinctorius).^[4] All parts of the plant Periploca laevigata contain heneicosane.^[5] Rosa damascena flower essential oil contains 5% heneicosane.^[6] Sambucus nigra contains 2.3%.