Acenaphthylene

Not to be confused with Acenaphthene.

Acenaphthylene

Skeletal formula Space-filling model
Names
Preferred IUPAC name Acenaphthylene
Other names Cyclopenta[de]naphthalene Acenaphthalene Tricyclo[6.3.1.04,12]dodeca-1(12),2,4,6,8,10-hexaene Tricyclo[6.3.1.04,12]dodecahexaene
Identifiers
CAS Number	208-96-8 checkY
3D model (JSmol)	Interactive image Interactive image
ChEBI	CHEBI:33081 checkY
ChemSpider	8807 checkY
ECHA InfoCard
E number
PubChem CID	9161
UNII	1Z25C36811 checkY
CompTox Dashboard (EPA)	{{#property:P3117}}
InChI InChI=1S/C12H8/c1-3-9-4-2-6-11-8-7-10(5-1)12(9)11/h1-8H checkY Key: HXGDTGSAIMULJN-UHFFFAOYSA-N checkY InChI=1/C12H8/c1-3-9-4-2-6-11-8-7-10(5-1)12(9)11/h1-8H Key: HXGDTGSAIMULJN-UHFFFAOYAQ
SMILES c3cc1cccc2\C=C/c(c12)c3 c1cc2cccc3c2c(c1)C=C3
Properties
Chemical formula	C12H8
Molar mass	152.196 g·mol−1
Appearance	Yellow crystals
Density	0.8987 g cm−3
Melting point	91.8 °C (197.2 °F; 364.9 K)
Boiling point	280 °C (536 °F; 553 K)
Solubility in water	Insoluble
Solubility in ethanol	very soluble
Solubility in diethyl ether	very soluble
Solubility in benzene	very soluble
Solubility in chloroform	soluble
Thermochemistry[1]
Heat capacity (C)	166.4 J mol−1 K−1
Enthalpy of fusion (ΔfH⦵fus)	186.7 kJ/mol
Enthalpy of vaporization (ΔfHvap)	69 kJ/mol
Enthalpy of sublimation (ΔfHsublim)	71.06 kJ/mol
Hazards
GHS labelling:
Pictograms	GHS06: ToxicGHS07: Exclamation mark
Signal word	Danger
Hazard statements	H302, H310, H315, H319, H330, H335
Precautionary statements	P260, P261, P262, P264, P270, P271, P280, P284, P301+P312, P302+P350, P302+P352, P304+P340, P305+P351+P338, P310, P312, P320, P321, P322, P330, P332+P313, P337+P313, P361, P362, P363, P403+P233, P405, P501
Flash point	122 °C (252 °F; 395 K)
Related compounds
Related compounds	acenaphthene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). checkY verify (what is checkY☒N ?) Infobox references

Acenaphthylene, a polycyclic aromatic hydrocarbon is an ortho- and peri-fused tricyclic hydrocarbon. The molecule resembles naphthalene with positions 1 and 8 connected by a -CH=CH- unit. It is a yellow solid. Unlike many polycyclic aromatic hydrocarbons, it has no fluorescence.

Occurrence

Acenaphthylene occurs as about 2% of coal tar. It is produced industrially by gas phase dehydrogenation of acenaphthene.

Reactions

Hydrogenation gives the more saturated compound acenaphthene. Chemical reduction affords the radical anion sodium or potassium acenaphthalenide, which is used as a strong reductant (E = -2.26 V vs FC).

It functions as a ligand for some organometallic compounds.

Uses

Polymerisation of acenaphthylene with acetylene in the presence of a Lewis acid catalyst gives electrically conductive polymers. Acenaphthylene possesses excellent properties as an antioxidant in cross-linked polyethylene and ethylene-propylene rubber. Thermal trimerization of acenaphthylene leads to decacyclene, which can be further processed to sulfur dyes.

Toxicity

The no-observed-adverse-effect-level of acenaphthylene after repeated 28-day oral administration to both male and female rats was found to be 4 mg/kg/day.