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 ( versus 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.Ullmann, 4th ed., 21, 70
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.
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