Role of Phenyl Radicals in the Growth of Polycyclic Aromatic Hydrocarbons

Citations Over TimeTop 10% of 2008 papers

Abstract

To investigate the role of phenyl radical in the growth of PAHs (polycyclic aromatic hydrocarbons), pyrolysis of toluene with and without benzene has been studied by using a heatable tubular reactor couple with an in-situ sampling vacuum ultraviolet (VUV) single photon ionization (SPI) time-of-flight mass spectrometer (TOFMS) at temperatures 1155-1467 K and a pressure of 10.02 Torr with 0.56 s residence time. When benzene was added, a significant increase of phenyl addition products (biphenyl, terphenyl, and triphenylene) was observed and the mass spectra showed a clear regular sequence with an interval of approximately 74 mass number, corresponding to the phenyl addition (+C6H5) followed by H-elimination (-H) and cyclization (-H2). The analysis showed that the PAC (phenyl addition/cylization) mechanism is efficient for the growth of PAHs without a triple fusing site, for which the HACA (hydrogen abstraction/C2H2 addition) step is inefficient, and produces PAHs with five-membered rings. The PAC process was also suggested to be efficient in the subsequent growth of PAHs with five-membered rings. The role of the PAC mechanism in combustion conditions is discussed in relation to the importance of disordered five-membered ring structure in fullerene or soot core.

Related Papers

• → Solubilities of Mixed Acenaphthene, Fluoranthene, and Triphenylene in Supercritical Carbon Dioxide and the Separation of Binary Solid Mixtures of Polycyclic Aromatic Hydrocarbons(2000)17 cited
• → Separation and Characterization of Mononitro Derivatives of Phenanthrene, Pyrene, Chrysene, Fluoranthene and Triphenylene.(1983)34 cited
• → Determination of polynuclear aromatic hydrocarbons in vapor phases by laser-induced molecular fluorescence(1983)21 cited
• → 1,3-Dipolar cycloaddition reactions of polycyclic aromatic hydrocarbons with 3,5-dichloro-2,4,6-trimethyl- and 2,4,6-trimethylbenzonitrile oxide(1996)13 cited
• → Electronic Communication in the Formation of a Quartet Molecule 2,6,10-Tris[bis(p-methoxyphenyl)aminium]triphenylene(2010)4 cited