Indene formation from alkylated aromatics: Kinetics and products of the fulvenallene acetylene reaction

Abstract

A novel reaction is described for formation of the polyaromatic hydrocarbon (PAH) indene in aromatic flames, via the reaction of fulvenallene with acetylene (C2H2). Fulvenallene has been recently identified as the major decomposition product of the benzyl radical, the dominant intermediate in the oxidation of alkylated aromatic hydrocarbons, yet it is not presently included in kinetic models for aromatic oxidation or PAH/soot formation. Ab initio calculations with the G3B3 theoretical method show that acetylene adds to fulvenallene with a barrier of around 27 kcal mol -1. This forms an activated C9H8 adduct that can rearrange to indene and dissociate to 1-indenyl + H with energy barriers bel..