Photoionization mass and photoelectron spectroscopy of radicals, carbenes, and biradicals

Blush, Joel A.; Clauberg, Horst; Köhn, Daniel; Minsek, David W.; Zhang, Xu; Chen, Peter

doi:10.1021/ar00021a001

Cited by 90 publications

(66 citation statements)

References 54 publications

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“…The signal is thus not due to dissociative ionization of propargyl and we assume that a small amount of C 3 H 2 is formed in the pyrolysis source. However, there are three different isomers of this composition: propadienylidene with a high ionization potential IE= 10.43 eV is not detectable by ͓1+1Ј͔ ionization in our experiment; 59 the IEs of the two other isomers, cyclopropenylidene ͓IE = 9.15 eV ͑Ref. 59͔͒ and propargylene ͓IEϷ 8.96 eV ͑Ref.…”

Section: Other Speciescontrasting

confidence: 59%

Excited-state decay of hydrocarbon radicals, investigated by femtosecond time-resolved photoionization: Ethyl, propargyl, and benzyl

Zierhut

Noller

Schultz

et al. 2005

The Journal of Chemical Physics

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The excited state decay of the hydrocarbon radicals ethyl, C 2 H 5 ; propargyl, C 3 H 3 ; and benzyl, C 7 H 7 was investigated by femtosecond time-resolved photoionization. Radicals were generated by flash pyrolysis of n-propyl nitrite, propargyl bromide, and toluene, respectively. It is shown that the 2 2 AЈ ͑3s͒ Rydberg state of ethyl excited at 250 nm decays with a time constant of 20 fs. No residual signal was observed at longer delay times. For the 3 2 B 1 state of propargyl excited at 255 nm a slower decay with a time constant 50± 10 fs was determined. The 4 2 B 2 state of benzyl excited at 255 nm decays within 150± 30 fs.

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Section: Other Speciescontrasting

confidence: 59%

Excited-state decay of hydrocarbon radicals, investigated by femtosecond time-resolved photoionization: Ethyl, propargyl, and benzyl

Zierhut

Noller

Schultz

et al. 2005

The Journal of Chemical Physics

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“…The purpose of the experiments presented here is to identify the products of butyraldehyde pyrolysis by using a hyperthermal nozzle (Chen nozzle) [15][16][17] and matrix-isolation Fourier transform infrared (FTIR) spectroscopy. The hyperthermal nozzle provided an oxygen-free environment for thermal decomposition of gas-phase butyraldehyde, while matrixisolation FTIR was used to detect the products.…”

Section: Cho + → Ch 3 + [Hco]mentioning

confidence: 99%

Thermal decomposition products of butyraldehyde

Hatten

Kaskey

Warner

et al. 2013

The Journal of Chemical Physics

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The thermal decomposition of gas-phase butyraldehyde, CH3CH2CH2CHO, was studied in the 1300-1600 K range with a hyperthermal nozzle. Products were identified via matrix-isolation Fourier transform infrared spectroscopy and photoionization mass spectrometry in separate experiments. There are at least six major initial reactions contributing to the decomposition of butyraldehyde: a radical decomposition channel leading to propyl radical + CO + H; molecular elimination to form H2 + ethylketene; a keto-enol tautomerism followed by elimination of H2O producing 1-butyne; an intramolecular hydrogen shift and elimination producing vinyl alcohol and ethylene, a β-C-C bond scission yielding ethyl and vinoxy radicals; and a γ-C-C bond scission yielding methyl and CH2CH2CHO radicals. The first three reactions are analogous to those observed in the thermal decomposition of acetaldehyde, but the latter three reactions are made possible by the longer alkyl chain structure of butyraldehyde. The products identified following thermal decomposition of butyraldehyde are CO, HCO, CH3CH2CH2, CH3CH2CH=C=O, H2O, CH3CH2C≡CH, CH2CH2, CH2=CHOH, CH2CHO, CH3, HC≡CH, CH2CCH, CH3C≡CH, CH3CH=CH2, H2C=C=O, CH3CH2CH3, CH2=CHCHO, C4H2, C4H4, and C4H8. The first ten products listed are direct products of the six reactions listed above. The remaining products can be attributed to further decomposition reactions or bimolecular reactions in the nozzle.

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“…nonzero signal, extending below 9 eV. Chen and co-workers [23,39] used VUV photoionization mass and photoelectron spectroscopy to determine adiabatic IPs for cyclopropenylidene and propadienylidene to be 9.15 AE 0.03 eV and 10.43 AE 0.02 eV, respectively. These values were compared to corrected additivity and scaled ab initio results.…”

Section: Allenementioning

confidence: 99%

Photofragment translational spectroscopy of allene, propyne, and propyne-d3 at 193 nm

et al. 2005

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The dissociation dynamics of allene, propyne, and propyne-d 3 at 193 nm were investigated with photofragment translational spectroscopy. Products were either photoionized using tunable VUV synchrotron radiation or ionized with electron impact. Product time-of-flight data were obtained to determine centre-of-mass translational energy (P(E T )) distributions, and photoionization efficiency (PIE) curves were measured for the hydrocarbon products. The two major product channels evident from this study are atomic and molecular hydrogen loss, with a H:H 2 branching ratio of 90:10, regardless of precursor. The P(E T ) distribution for each channel is also largely independent of precursor. Both channels appear to occur following internal conversion to the ground electronic state. The propyne-d 3 results show that there is extensive isotopic scrambling prior to H(D) atom loss, and that the H:D product ratio is approximately unity. The PIE curves for H(D) atom loss from allene, propyne, and propyne-d 3 indicate that the dominant corresponding C 3 H 3 product is the propargyl radical in all cases. There is some evidence from the PIE curves that the dominant C 3 H 2 products from allene and propyne are propadienylidene (H 2 CCC:) and propargylene (HCCCH), respectively.

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Photoionization mass and photoelectron spectroscopy of radicals, carbenes, and biradicals

Cited by 90 publications

References 54 publications

Excited-state decay of hydrocarbon radicals, investigated by femtosecond time-resolved photoionization: Ethyl, propargyl, and benzyl

Excited-state decay of hydrocarbon radicals, investigated by femtosecond time-resolved photoionization: Ethyl, propargyl, and benzyl

Thermal decomposition products of butyraldehyde

Photofragment translational spectroscopy of allene, propyne, and propyne-d3 at 193 nm

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