Unexpected Chemistry from the Reaction of Naphthyl and Acetylene at Combustion‐Like Temperatures

Parker, Dorian S. N.; Kaiser, Ralf I.; Bandyopadhyay, Biswajit; Kostko, Oleg; Troy, Tyler P.; Ahmed, Musahid

doi:10.1002/ange.201411987

Cited by 35 publications

(47 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on recent literature, this stabilomer species appears to be a likely product of the HACA mechanism. 21,31,61 Hence, our PIE results at 200 u suggest that other chemical-growth mechanisms than HACA are important in this flame.…”

Section: Discussionmentioning

confidence: 66%

“…14 Despite these challenges, PIE measurements have been used to separate isomers of larger species in chemically limited systems, i.e., in systems with a limited number of possible isomers. For example, Zhang et al 20 distinguished indene (C9H8) from three of its isomers by comparing experiments and simulated photoionization cross-section curves, and Parker et al 21 similarly inferred contributions to the signal at 152 u from 2-ethynyl-naphthalene and acenaphthylene (C12H8).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Critical Assessment of Photoionization Efficiency Measurements for Characterization of Soot-Precursor Species

et al. 2017

View full text Add to dashboard Cite

We present a critical evaluation of photoionization efficiency (PIE) measurements coupled with aerosol mass spectrometry for the identification of condensed soot-precursor species extracted from a premixed atmospheric-pressure ethylene/oxygen/nitrogen flame. Definitive identification of isomers by any means is complicated by the large number of potential isomers at masses likely to comprise particles at flame temperatures. This problem is compounded using PIE measurements by the similarity in ionization energies and PIE-curve shapes among many of these isomers. Nevertheless, PIE analysis can provide important chemical information. For example, our PIE curves show that neither pyrene nor fluoranthene alone can describe the signal from C16H10 isomers and that coronene alone cannot describe the PIE signal from C24H12 species.A linear combination of the reference PIE curves for pyrene and fluoranthene yields good agreement with flame-PIE curves measured at 202 u, which is consistent with pyrene and fluoranthene being the two major C16H10 isomers in the flame samples, but does not provide definite proof. The suggested ratio between fluoranthene and pyrene depends on the sampling conditions. We calculated the values of the adiabatic-ionization energy (AIE) of twenty-four C16H10 isomers. Despite the small number of isomers considered, the calculations show that the differences in AIEs between several of the isomers can be smaller than the average thermal energy at room temperature. The calculations also show that PIE analysis can sometimes be used to separate hydrocarbon species into those that contain mainly aromatic rings and those that contain significant aliphatic content for species sizes investigated in this study. Our calculations suggest an inverse relationship between AIE and the number of aromatic rings. We have demonstrated that further characterization of precursors can be facilitated by measurements that test species volatility.3

show abstract

Section: Discussionmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

Critical Assessment of Photoionization Efficiency Measurements for Characterization of Soot-Precursor Species

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Further, extended residence times promote higher order reactions as evident from the naphthalene, acenaphthylene, and biphenyl products formed in the NSRL studies, which can be formed via phenyl -vinylacetylene 86 , naphthyl -acetylene 87 , and phenyl -benzene 88 reactions as verified in prior studies. Therefore, future studies on JP-10 decomposition should not explore only the effects of the temperature, but also systematically how the products and their branching ratios depend on the pressure and residence times in the reactor, Finally, subsequent studies should also probe the oxidation mechanisms of JP-10.…”

mentioning

confidence: 73%

A vacuum ultraviolet photoionization study on high-temperature decomposition of JP-10 (exo-tetrahydrodicyclopentadiene)

Zhao

Yang

Kaiser

et al. 2017

Phys. Chem. Chem. Phys.

Self Cite

121

View full text Add to dashboard Cite

Two sets of experiments were performed to unravel the high-temperature pyrolysis of tricyclo[5.2.1.0 2,6 ] decane (JP-10) exploiting high-temperature reactors over a temperature range of 1100 K to 1600 K Advanced Light Source (ALS) and 927 K to 1083 K National Synchrotron Radiation Laboratory (NSRL)with residence times of a few tens of microseconds (ALS) to typically 144 ms (NSRL). The products were identified in situ in supersonic molecular beams via single photon vacuum ultraviolet (VUV) photoionization coupled with mass spectroscopic detection in a reflectron time-of-flight mass spectrometer (ReTOF). These studies were designed to probe the initial (ALS) and also higher order reaction products (NSRL) formed in the decomposition of JP-10 -including radicals and thermally labile closed-shell species. Altogether 43 products were detected and quantified including C1-C4 alkenes, dienes, C3-C4 cumulenes, alkynes, eneynes, diynes, cycloalkenes, cyclo-dienes, aromatic molecules, and most important, radicals such as ethyl, allyl, and methyl produced at lower residence times. At longer residence times, the predominant fragments are molecular hydrogen (H2), ethylene (C2H4), propene (C3H6), cyclopentadiene (C5H6), cyclopentene (C5H8), fulvene (C6H6), and benzene (C6H6).Accompanied by electronic structure calculations, the initial JP-10 decomposition via C-H bond cleavages resulting in the formation of initially six C10H15 radicals were found to explain the formation of all products detected in both sets of experiments. These radicals are not stable under the experiment conditions and further decompose via C-C bond -scission processes. These pathways result in ring opening in the initial tricyclic carbon skeletons of JP-10. Intermediates accessed after the first -scission can further isomerize or dissociate. Complex PAH products in the NRLS experiment (naphthalene, acenaphthylene, biphenyl) are likely formed via molecular growth reactions at elevated residence times.3

show abstract

“…State-of-the-art astrochemical models of PAH formation have been 'borrowed' from the combustion chemistry community with the most commended pathways to PAHs proposed to be associated with molecular weight growth processes via sequential reactions of resonantly stabilized (propargyl; C3H3) and also aromatic (phenyl; C6H5) radicals. Together with acetylene (C2H2), these reactions are contemplated as the foundation for the hydrogen abstraction -acetylene addition (HACA) mechanism [14][15][16][17][18][19] driving PAH synthesis at elevated temperatures of up to a few 1,000 K. Supportive electronic structure calculations 18,[20][21][22][23][24] and kinetic modeling 14,[25][26][27] suggests that HACA involves a repetitive sequence of atomic hydrogen abstraction from the reacting aromatic hydrocarbon followed by sequential addition of two acetylene molecules to the radical sites prior to cyclization and aromatization 12,[15][16]20,26,28 .…”

mentioning

confidence: 99%

VUV Photoionization Study of the Formation of the Simplest Polycyclic Aromatic Hydrocarbon: Naphthalene (C₁₀H₈)

Zhao

Kaiser

et al. 2018

J. Phys. Chem. Lett.

Self Cite

View full text Add to dashboard Cite

The formation of the simplest polycyclic aromatic hydrocarbon (PAH), naphthalene (CH), was explored in a high-temperature chemical reactor under combustion-like conditions in the phenyl (CH)-vinylacetylene (CH) system. The products were probed utilizing tunable vacuum ultraviolet light by scanning the photoionization efficiency (PIE) curve at a mass-to-charge m/ z = 128 (CH) of molecules entrained in a molecular beam. The data fitting with PIE reference curves of naphthalene, 4-phenylvinylacetylene (CHCCCH), and trans-1-phenylvinylacetylene (CHCHCHCCH) indicates that the isomers were generated with branching ratios of 43.5±9.0 : 6.5±1.0 : 50.0±10.0%. Kinetics simulations agree nicely with the experimental findings with naphthalene synthesized via the hydrogen abstraction-vinylacetylene addition (HAVA) pathway and through hydrogen-assisted isomerization of phenylvinylacetylenes. The HAVA route to naphthalene at elevated temperatures represents an alternative pathway to the hydrogen abstraction-acetylene addition (HACA) forming naphthalene in flames and circumstellar envelopes, whereas in cold molecular clouds, HAVA synthesizes naphthalene via a barrierless bimolecular route.

show abstract

Unexpected Chemistry from the Reaction of Naphthyl and Acetylene at Combustion‐Like Temperatures

Cited by 35 publications

References 30 publications

Critical Assessment of Photoionization Efficiency Measurements for Characterization of Soot-Precursor Species

Critical Assessment of Photoionization Efficiency Measurements for Characterization of Soot-Precursor Species

A vacuum ultraviolet photoionization study on high-temperature decomposition of JP-10 (exo-tetrahydrodicyclopentadiene)

VUV Photoionization Study of the Formation of the Simplest Polycyclic Aromatic Hydrocarbon: Naphthalene (C₁₀H₈)

Contact Info

Product

Resources

About

Unexpected Chemistry from the Reaction of Naphthyl and Acetylene at Combustion‐Like Temperatures

Cited by 35 publications

References 30 publications

Critical Assessment of Photoionization Efficiency Measurements for Characterization of Soot-Precursor Species

Critical Assessment of Photoionization Efficiency Measurements for Characterization of Soot-Precursor Species

A vacuum ultraviolet photoionization study on high-temperature decomposition of JP-10 (exo-tetrahydrodicyclopentadiene)

VUV Photoionization Study of the Formation of the Simplest Polycyclic Aromatic Hydrocarbon: Naphthalene (C10H8)

Contact Info

Product

Resources

About

VUV Photoionization Study of the Formation of the Simplest Polycyclic Aromatic Hydrocarbon: Naphthalene (C₁₀H₈)