The Electronic Spectrum of the Fulvenallenyl Radical

Chakraborty, Arghya; Fulara, Jan; Maier, John P.

doi:10.1002/anie.201508961

Cited by 8 publications

(10 citation statements)

References 53 publications

(62 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, these closed-shell species are not expected to absorb light near 400 nm. The electronic spectrum of the fulvenallenyl radical in low-temperature neon matrices was recently reported . The absorption band observed at 401.3 nm was assigned to the 1 2 B 1 ← X 2 B 1 transition (in their notation) of the fulvenallenyl radical, which corresponds well with the wavelength region where the transient absorption was observed in the present study.…”

Section: Resultssupporting

confidence: 86%

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

Matsugi

2020

J. Phys. Chem. A

View full text Add to dashboard Cite

Understanding the mechanism of high-temperature reactions of aromatic hydrocarbons and radicals is essential for the modeling of hydrocarbon growth processes in combustion environments. In this study, the thermal decomposition reaction of benzyl radicals was investigated using time-resolved broadband cavity-enhanced absorption spectroscopy behind reflected shock waves at a postshock pressure of 100 kPa and temperatures of 1530, 1630, and 1740 K. The transient absorption spectra during the decomposition were recorded over the spectral range of 282−410 nm. The spectra were contributed by the absorption of benzyl radicals and some transient and residual absorbing species. The temporal behavior of the absorption was analyzed using a kinetic model to determine the rate constant for benzyl decomposition. The obtained rate constants can be represented by the Arrhenius expression k 1 = 1.1 × 10 12 exp(−30 500 K/T) s −1 with an estimated logarithmic uncertainty of Δlog 10 k = ±0.2. Kinetic simulation of the secondary reactions indicated that fulvenallenyl radicals are potentially responsible for the transient absorption that appeared around 400 nm. This assignment is consistent with the available spectroscopic information of this radical. Possible candidates for the residual absorbing species are presented, suggesting the potential importance of ortho-benzyne as a reactive intermediate.

show abstract

Section: Resultssupporting

confidence: 86%

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

Matsugi

2020

J. Phys. Chem. A

View full text Add to dashboard Cite

show abstract

“…The ground state was identified as having B 1 symmetry, in agreement with previous theoretical work. 24 However, a low-lying A 2 symmetry electronic state was also found. It was less than 8000 cm −1 higher in energy than the B 1 state, at the B 1 optimized geometry.…”

Section: Computational Detailsmentioning

confidence: 98%

“…16,22−24 The electronic spectrum of fulvenallenyl in a neon matrix was recorded following mass selective deposition of its anion and UV irradiation. 24 The 1 2 B 1 ← X 2 B 1 transition was observed at λ = 401.3 nm along with 3 vibrational bands at 365 (ν 19 ), 1984 (ν 4 ), and 3958 cm −1 (2ν 4 ). Photoelectron spectroscopy of fulvenallenyl determined its adiabatic ionization energy to be 8.19 eV.…”

Section: Introductionmentioning

confidence: 95%

Infrared Spectrum of Fulvenallene and Fulvenallenyl in Helium Droplets

et al. 2019

View full text Add to dashboard Cite

Fulvenallene is the global minimum on the C7H6 potential energy surface. Rearrangement of fulvenallene to other C7H6 species and dissociation to produce fulvenallenyl radical (C7H5) is carried out in a continuous-wave SiC pyrolysis furnace at 1500 K. Prompt pick-up and solvation by helium droplets allows for the acquisition of vibrational spectra of these species in the CH stretching region. Anharmonic frequencies for fulvenallene, fulvenallenyl, and three isomers of ethynylcyclopentadiene are computed ab initio; VPT2+K spectral simulations are based on hybrid CCSD(T) force fields with quadratic (cubic and quartic) force constants computed using the ANO1 (ANO0) basis set. The acetylenic CH stretch of the fulvenallenyl radical is a sensitive marker of the extent by which the unpaired electron is delocalized throughout the conjugated propargyl and cyclopentadienyl subunits. The nature of this electron delocalization is explored with spin density calculations at the ROHF-CCSD(T)/ANO1 level of theory. Atomic partitioning of the spin density allows for a description of the fulvenallenyl radical in terms of two resonance structures: fulvenallenyl is approximately 24% allenic and 76% acetylenic.

show abstract

“…The main impuissance of these techniques is that they are not species‐selective. With this concern, the approach involving isolation of mass‐selected ions and their neutralization in solid neon serves a pivotal role in the spectroscopic characterization of transient organic intermediates …”

Section: Figurementioning

confidence: 99%

Electronic Characterization of Reaction Intermediates: The Fluorenylium, Phenalenylium, and Benz[f]indenylium Cations and Their Radicals

2016

Self Cite

View full text Add to dashboard Cite

Three vibrationally resolved absorption systems commencing at 538, 518, and 392 nm were detected in a 6 K neon matrix after mass-selected deposition of C13 H9 (+) ions (m/z=165) produced from fluorene in a hot-cathode discharge ion source. The benz[f]indenylium (BfI(+) : 538 nm), fluorenylium (FL9(+) : 518 nm), and phenalenylium (PHL(+) : 392 nm) cations are the absorbing molecules. Two electronic systems corresponding to neutral species are apparent at 490 and 546 nm after irradiation of the matrix with λ<260 nm photons and were assigned to the FL9 and BfI radicals, respectively. The strongest peak at 518 nm is the origin of the 2 (1) B2 ←X̃ (1) A1 absorption of FL9(+) , and the 490 nm band is the 2 (2) A2 ←X̃ (2) B1 origin of FL9. The electronic systems commencing at 538 nm and 546 nm were assigned to the 1 (1) A1 ←X̃ (1) A1 and 1 (2) A2 ←X̃ (2) A2 transitions of BfI(+) and BfI. The 392 nm band is the 1 (1) E'←X̃ (1) A1 ' transition of PHL(+). The electronic spectra of C13 H9 (+) /C13 H9 were assigned on the basis of the vertical excitation energies calculated with SAC-CI and MS-CASPT2 methods.

show abstract

The Electronic Spectrum of the Fulvenallenyl Radical

Cited by 8 publications

References 53 publications

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

Infrared Spectrum of Fulvenallene and Fulvenallenyl in Helium Droplets

Electronic Characterization of Reaction Intermediates: The Fluorenylium, Phenalenylium, and Benz[f]indenylium Cations and Their Radicals

Contact Info

Product

Resources

About