Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Selective Formation of Indene through the Reaction of Benzyl Radicals with Acetylene

Journal Article · · ChemPhysChem
 [1];  [2];  [3];  [3]
  1. Univ. of Hawaii at Manoa, Honolulu, HI (United States); University of Hawaii at Manoa
  2. Univ. of Hawaii at Manoa, Honolulu, HI (United States)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
+ Show Author Affiliations

The combustion of fossil fuels forms polycyclic aromatic hydrocarbons (PAHs) composed of five- and six- membered aromatic rings, such as indene (C9H8), which are carcinogenic, mutagenic, and deleterious to the environment. Indene, the simplest PAH with single five- and six-membered rings, has been predicted theoretically to be formed through the reaction of benzyl radicals with acetylene. Benzyl radicals are found in significant concentrations in combustion flames, owing to their highly stable aromatic and resonantly stabilized free-radical character. We provide compelling experimental evidence that indene is synthesized through the reaction of the benzyl radical (C7H7) with acetylene (C2H2) under combustion-like conditions at 600 K. The mechanism involves an initial addition step followed by cyclization and aromatization through atomic hydrogen loss. This reaction was found to form the indene isomer exclusively, which, in conjunction with the high concentrations of benzyl and acetylene in combustion environments, indicates that this pathway is the predominant route to synthesize the prototypical five- and six-membered PAH.

Research Organization:
Univ. of Hawaii at Manoa, Honolulu, HI (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
FG02-03ER15411
OSTI ID:
1602914
Journal Information:
ChemPhysChem, Journal Name: ChemPhysChem Journal Issue: 10 Vol. 16; ISSN 1439-4235
Publisher:
ChemPubSoc EuropeCopyright Statement
Country of Publication:
United States
Language:
English

References (30)

Hydrogen Abstraction/Acetylene Addition Revealed journal June 2014
Hydrogen Abstraction/Acetylene Addition Revealed journal June 2014
Indene Formation under Single-Collision Conditions from the Reaction of Phenyl Radicals with Allene and Methylacetylene-A Crossed Molecular Beam and Ab Initio Study journal September 2011
Carcinogenic polycyclic aromatic hydrocarbon-DNA adducts and mechanism of action journal January 2005
Determination of absolute photoionization cross-sections of aromatics and aromatic derivatives journal December 2009
Kinetic modeling of counterflow diffusion flames of butadiene journal November 2002
Aromatic and Polycyclic Aromatic Hydrocarbon Formation in a Laminar Premixed n-Butane Flame journal July 1998
The effects of equivalence ratio on the formation of polycyclic aromatic hydrocarbons and soot in premixed ethane flames journal June 2000
Detailed modeling of soot particle nucleation and growth journal January 1991
Composition profiles and reaction mechanisms in a near-sooting premixed benzene/oxygen/argon flame journal January 1981
Experimental and modeling investigation of aromatic and polycyclic aromatic hydrocarbon formation in a premixed ethylene flame journal January 1996
Formation of polycyclic aromatic hydrocarbons and their growth to soot—a review of chemical reaction pathways journal August 2000
PAH Growth from the pyrolysis of CPD, indene and naphthalene mixture journal April 2004
Formation of small PAHs in laminar premixed low-pressure propene and cyclopentene flames: Experiment and modeling journal January 2008
Investigation on fuel-rich premixed flames of monocyclic aromatic hydrocarbons: Part I. Intermediate identification and mass spectrometric analysis journal January 2010
Thermal decomposition of toluene: Overall rate and branching ratio journal January 2007
Molecular Reaction Dynamics book January 2005
Bond Dissociation Energies of Organic Molecules journal April 2003
Hydrogen Abstraction Acetylene Addition and Diels−Alder Mechanisms of PAH Formation:  A Detailed Study Using First Principles Calculations journal September 2005
Experimental Study of a Fuel-Rich Premixed Toluene Flame at Low Pressure journal March 2009
Proposed fullerene precursor corannulene identified in flames both in the presence and absence of fullerene production journal December 1993
An Instance of Trivalent Carbon: Triphenylmethyl. journal November 1900
Vacuum Ultraviolet Photoionization of C3 journal December 2005
Formation of Naphthalene, Indene, and Benzene from Cyclopentadiene Pyrolysis:  A DFT Study journal April 2006
Ab Initio G3-type/Statistical Theory Study of the Formation of Indene in Combustion Flames. I. Pathways Involving Benzene and Phenyl Radical † journal May 2007
A VUV Photoionization Study of the Formation of the Indene Molecule and Its Isomers journal June 2011
Theoretical study of benzyl radical reactivity in combustion systems
  • M. Davis, William; M. Heck, Simone; O. Pritchard, Huw
  • Journal of the Chemical Society, Faraday Transactions, Vol. 94, Issue 18 https://doi.org/10.1039/a804131h
journal January 1998
Reactions of chemically activated C9H9 species II: The reaction of phenyl radicals with allene and cyclopropene, and of benzyl radicals with acetyleneElectronic supplementary information (ESI) available: Full [C9H9] reaction scheme. Additional quantum chemical calculations not reported yet in earlier publications. Full product distribution and over-all rate coefficient listings, both uncorrected and effective data, for all reaction conditions examined. For the most important products, tables are included listing the yield as function of temperature and pressure. Modified Arrhenius fits for the over-all TST rate coefficient and the TST rate coefficient of the different entrance channels are listed for different temperature intervals. See http://www.rsc.org/suppdata/cp/b3/b303908k/ or contact the authors directly, or download from the website http://arrhenius.chem.kuleuven.ac.be. journal January 2003
Flash pyrolysis nozzle for generation of radicals in a supersonic jet expansion journal August 1992
Tropospheric Air Pollution: Ozone, Airborne Toxics, Polycyclic Aromatic Hydrocarbons, and Particles journal May 1997

Cited By (6)

Reactivity of the Indenyl Radical (C 9 H 7 ) with Acetylene (C 2 H 2 ) and Vinylacetylene (C 4 H 4 ) journal April 2019
Low-temperature formation of polycyclic aromatic hydrocarbons in Titan’s atmosphere journal October 2018
A Barrierless Pathway Accessing the C9H9 and C9H8 Potential Energy Surfaces via the Elementary Reaction of Benzene with 1-Propynyl journal November 2019
On the formation and the isomer specific detection of methylacetylene (CH 3 CCH), propene (CH 3 CHCH 2 ), cyclopropane (c-C 3 H 6 ), vinylacetylene (CH 2 CHCCH), and 1,3-butadiene (CH 2 CHCHCH 2 ) from interstellar methane ice analogues journal January 2019
How to add a five-membered ring to polycyclic aromatic hydrocarbons (PAHs) – molecular mass growth of the 2-naphthyl radical (C 10 H 7 ) to benzindenes (C 13 H 10 ) as a case study journal January 2019
Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis of Acetylene (C 2 H 2 ) and D2-acetylene (C 2 D 2 ) Ices Exposed to Ionizing Radiation via Ultraviolet–Visible Spectroscopy, Infrared Spectroscopy, and Reflectron Time-of-flight Mass Spectrometry journal January 2020

Similar Records

Formation Mechanisms of Naphthalene and Indene: From the Interstellar Medium to Combustion Flames
Journal Article · Mon Jan 09 23:00:00 EST 2017 · Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory · OSTI ID:1602961

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
combustion
gas‐phase chemistry
mass spectrometry
polycyclic aromatic hydrocarbons
radicals