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Reaction Dynamics of the 4-Methylphenyl Radical ( p -Tolyl) with 1,2-Butadiene (1-Methylallene): Are Methyl Groups Purely Spectators?

Journal Article · · Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
DOI:https://doi.org/10.1021/jp505868q· OSTI ID:1602873
 [1];  [2];  [2];  [2];  [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. Florida International Univ., Miami, FL (United States)
+ Show Author Affiliations

The reactions of the 4-tolyl radical (C6H4CH3) and of the D7-4-tolyl radical (C6D4CD3) with 1,2-butadiene (C4H6) have been probed in crossed molecular beams under single collision conditions at a collision energy of about 54 kJ mol-1 and studied theoretically using ab initio G3(MP2,CC)//B3LYP/6-311G** and statistical RRKM calculations. The results show that the reaction proceeds via indirect scattering dynamics through the formation of a van-der-Waals complex followed by the addition of the radical center of the 4-tolyl radical to the C1 or C3 carbon atoms of 1,2-butadiene. The collision complexes then isomerize by migration of the tolyl group from the C1 (C3) to the C2 carbon atom of the 1,2-butadiene moiety. The resulting intermediate undergoes unimolecular decomposition via elimination of a hydrogen atom from the methyl group of the 1,2-butadiene moiety through a rather loose exit transition state leading to 2-para-tolyl-1,3-butadiene (p4), which likely presents the major reaction product. Our observation combined with theoretical calculations suggest that one methyl group (at the phenyl group) acts as a spectator in the reaction, whereas the other one (at the allene moiety) is actively engaged in the underlying chemical dynamics. On the contrary to the reaction of the phenyl radical with allene, which leads to the formation of indene, the substitution of a hydrogen atom by a methyl group in allene essentially eliminates the formation of bicyclic PAHs such as substituted indenes in the 4-tolyl plus 1,2-butadiene reaction.

Research Organization:
Univ. of Hawaii at Manoa, Honolulu, HI (United States); Florida International Univ., Miami, FL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
FG02-03ER15411; FG02-04ER15570
OSTI ID:
1602873
Journal Information:
Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory, Journal Name: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory Journal Issue: 32 Vol. 118; ISSN 1089-5639
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English

References (39)

Kinetics and products of propargyl (C3H3) radical self-reactions and propargyl-methyl cross-combination reactions journal January 2000
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
Soot Formation in Combustion Processes (Review) journal November 2005
Three dissociation channels for p-dichlorobenzene excited at 193 nm in molecular beams journal November 1985
Gaussian-3 theory using coupled cluster energies journal November 1999
Kinetic modeling of counterflow diffusion flames of butadiene journal November 2002
Evidence that polycyclic aromatic hydrocarbons in two carbonaceous chondrites predate parent-body formation journal April 2003
Formation of polycyclic aromatic hydrocarbons and their radicals in a nearly sooting premixed benzene flame journal January 2000
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
An experimental and theoretical study of toluene pyrolysis with tunable synchrotron VUV photoionization and molecular-beam mass spectrometry journal November 2009
Investigation on fuel-rich premixed flames of monocyclic aromatic hydrocarbons: Part I. Intermediate identification and mass spectrometric analysis journal January 2010
Reaction dynamics of the phenyl radical with 1,2-butadiene journal May 2009
Investigation of the rich premixed laminar acetylene/oxygen/argon flame: Comprehensive flame structure and special concerns of polyynes journal January 2009
Isomerization kinetics of benzylic and methylphenyl type radicals in single-ring aromatics journal January 2013
Molecular Reaction Dynamics book January 2005
Analysis of Mars analogue soil samples using solid-phase microextraction, organic solvent extraction and gas chromatography/mass spectrometry journal January 2011
Reaction Dynamics of Phenyl Radicals in Extreme Environments: A Crossed Molecular Beam Study journal February 2009
Ab Initio Calculation of Vibrational Absorption and Circular Dichroism Spectra Using Density Functional Force Fields journal November 1994
A direct mass spectrometric study of the mechanism of toluene pyrolysis at high temperatures journal June 1979
The Mechanism of the Sandmeyer and Meerwein Reactions journal June 1957
Identification of C 5 H x Isomers in Fuel-Rich Flames by Photoionization Mass Spectrometry and Electronic Structure Calculations journal April 2006
PAH Formation under Single Collision Conditions: Reaction of Phenyl Radical and 1,3-Butadiene to Form 1,4-Dihydronaphthalene journal April 2012
A Crossed Molecular Beam and Ab-Initio Investigation of the Reaction of Boron Monoxide (BO; X 2 Σ + ) with Methylacetylene (CH 3 CCH; X 1 A 1 ): Competing Atomic Hydrogen and Methyl Loss Pathways journal May 2013
An Experimental and Theoretical Study on the Formation of 2-Methylnaphthalene (C 11 H 10 /C 11 H 3 D 7 ) in the Reactions of the Para-Tolyl (C 7 H 7 ) and Para-Tolyl-d7 (C 7 D 7 ) with Vinylacetylene (C 4 H 4 ) journal April 2014
Kinetics of the Cyclopentadienyl + Acetylene, Fulvenallene + H, and 1-Ethynylcyclopentadiene + H Reactions journal February 2010
Crossed beam reaction of phenyl and D5-phenyl radicals with propene and deuterated counterparts—competing atomic hydrogen and methyl loss pathways journal January 2012
A crossed molecular beam and ab initio investigation of the exclusive methyl loss pathway in the gas phase reaction of boron monoxide (BO; X 2 Σ + ) with dimethylacetylene (CH 3 CCCH 3 ; X 1 A 1g ) journal January 2014
Reaction mechanism of soot formation in flames journal February 2002
Untangling the chemical evolution of Titan's atmosphere and surface–from homogeneous to heterogeneous chemistry journal January 2010
Photofragmentation of chlorotoluenes and dichlorobenzenes: Substituent effects on the dissociation mechanism, and angular distribution of the Cl fragment journal July 1997
Gaussian-3 (G3) theory for molecules containing first and second-row atoms journal November 1998
Gaussian-3 theory using density functional geometries and zero-point energies journal April 1999
Low temperature formation of naphthalene and its role in the synthesis of PAHs (Polycyclic Aromatic Hydrocarbons) in the interstellar medium journal December 2011
The Identification of Cyclopenta-Fused and Ethynyl-Substituted Polycyclic Aromatic Hydrocarbons in Benzene Droplet Combustion Products journal April 2000
Modeling the Unidentified Infrared Emission with Combinations of Polycyclic Aromatic Hydrocarbons journal February 1999
Ultraviolet irradiation of naphthalene in H 2 O ice: Implications for meteorites and biogenesis journal March 2001
Molecular Diffuse Interstellar Band Carriers in the Red Rectangle journal August 1995
Formation of C 6 H 6 Isomers by Recombination of Propynyl in the System Sodium Vapour/Propynylhalide journal January 1989

Cited By (2)

Gas Phase Formation of the Interstellar Molecule Methyltriacetylene journal June 2019
Formation of bicyclic polycyclic aromatic hydrocarbons (PAHs) from the reaction of a phenyl radical with cis -3-penten-1-yne journal January 2018

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Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
bimolecular reaction
combustion
gas-phase chemistry
physical-organic chemistry
reaction mechanism