1,5-Hexadiene

1,5-Hexadiene is the organic compound with the formula (CH₂)₂(CH=CH₂)₂. It is a colorless, volatile liquid. It is used as a crosslinking agent and precursor to a variety of other compounds.

1,5-Hexadiene

Names
Preferred IUPAC name Hexa-1,5-diene
Other names diallyl, biallyl, α,ω-Hexadiene
Identifiers
CAS Number	592-42-7
3D model (JSmol)	Interactive image
ChemSpider	11110
ECHA InfoCard	100.008.869
EC Number	209-754-7
PubChem CID	11598
UNII	4MTZ4764FI
CompTox Dashboard (EPA)	DTXSID4049323
InChI InChI=1S/C6H10/c1-3-5-6-4-2/h3-4H,1-2,5-6H2 Key: PYGSKMBEVAICCR-UHFFFAOYSA-N
SMILES C=CCCC=C
Properties
Chemical formula	C6H10
Molar mass	82.146 g·mol−1
Appearance	colorless liquid
Boiling point	59–60 °C (138–140 °F; 332–333 K)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H302, H305, H315, H319, H335, H336
Precautionary statements	P210, P233, P240, P241, P242, P243, P261, P264, P271, P280, P301+P310, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P312, P321, P331, P332+P313, P337+P313, P362, P370+P378, P403+P233, P403+P235, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis

1,5-Hexadiene is produced commercially by the ethenolysis of 1,5-cyclooctadiene:^[1]

(CH₂CH=CHCH₂)₂ + 2 CH₂=CH₂ → 2 (CH₂)₂CH=CH₂

The catalyst is derived from Re₂O₇ on alumina.

A laboratory-scale preparation involves reductive coupling of allyl chloride using magnesium:^[2]

2 ClCH₂CH=CH₂ + Mg → (CH₂CH=CH₂)₂ + MgCl₂