Electronic Spectrum of Cyclobutanone

Whitlock, Rodger F.; Duncan, A. B. F.

doi:10.1063/1.1675511

Cited by 30 publications

(8 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The ionization potential of cyclobutanone has been found to be 9.61 eV by the technique of photoelectron spectroscopy (8) and has been estimated to be 9.35 eV from optical spectroscopy (9). The photoelectron spectroscopy value and the value of 9.58 eV obtained in the present electron impact study correspond to the vertical Can.…”

Section: Discussionsupporting

confidence: 55%

Low Energy Electron Impact Ionization and Fragmentation: Cyclobutanone

Branton¹,

Pua²

1973

Can. J. Chem.

View full text Add to dashboard Cite

Cyclobutanone is shown to yield both C3H6+ and C2H,0+ ions on fragmentation under electron impact in a mass spectrometer. Using the energy distribution difference (EDD) technique the ionization energy of cyclobutanone is found to be 9.58 eV and the appearance potentials of the C3H6+ and C,H,O+ ions are found to be 9.85 and 10.53 eV, respectively. Dans un spectrometre de masse, on montre que la cyclobutanone lorsque soumis B un bombardement d'Clectrons, libere comme fragment a la fois des ions C3H6+ et C 2 H 2 0 + . En utilisant la technique impliquant la difference de distribution energetique (DDE), I'tnergie d'ionisation de la cyclobutanone est donnee comme Ctant 9.58 eV et les potentiels d'apparition des ions C3Hs+ et C,H,O+ comme ttant respectivement 9.85 et 10.53 eV.[Traduit par le journal]Can. J. Chem., 51, 624 (1973)

show abstract

Section: Discussionsupporting

confidence: 55%

Low Energy Electron Impact Ionization and Fragmentation: Cyclobutanone

Branton¹,

Pua²

1973

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…In the cycloketones the S 1 state derives from an n!p* promotion with an observed band maximum around 4.1-4.4 eV. [1][2][3][4] The S 1 state has been extensively investigated by fluorescence and fluorescence excitation, [5][6][7][8][9][10][11][12] absorption, [1,3,5,13,14] and time-resolved mass-spectrometry (TR-MS). [15] The S 2 state is due to an n!3s Rydberg excitation and occurs around 6.2 eV, above which follows the three 3p states at around 6.9 eV.…”

Section: Introductionmentioning

confidence: 99%

“…[15] The S 2 state is due to an n!3s Rydberg excitation and occurs around 6.2 eV, above which follows the three 3p states at around 6.9 eV. [16,17] The Rydberg states of the cycloketones have also been extensively investigated using absorption, [13,14,16,[18][19][20] resonance-enhanced multiphoton ionization (REMPI), [17,[21][22][23] electron ionization [4] as well as TR-MS. [24][25][26][27] The three cycloketones represent a set of molecules with an increasing number of internal degrees of freedom (27, 36, and 45) as well as different point-group symmetries (C s , C 2 , and C s for cyclobutanone, cyclopentanone and cyclohexanone, respectively) incorporating the same chromophore. Certain specific differences between the molecules are present which could influence the time-scale of excited-state dynamics.…”

Section: Introductionmentioning

confidence: 99%

Coherent Motion Reveals Non‐Ergodic Nature of Internal Conversion between Excited States

2012

View full text Add to dashboard Cite

We found that specific nuclear motion along low-frequency modes is effective in coupling electronic states and that this motion prevail in some small molecules. Thus, in direct contradiction to what is expected based on the standard models, the internal conversion process can proceed faster for smaller molecules. Specifically, we focus on the S(2) →S(1) internal conversion in cyclobutanone, cyclopentanone, and cyclohexanone. By means of time-resolved mass spectrometry and photoelectron spectroscopy the relative rate of this transition is determined to be 13:2:1. Remarkably, we observe coherent nuclear motion on the S(2) surface in a ring-puckering mode and motion along this mode in combination with symmetry considerations allow for a consistent explanation of the observed relative time-scales not afforded by only considering the density of vibrational states or other aspects of the standard models.

show abstract

“…The transmission characteristics of each of the filters were matched to excite specific portions of the n -»• * transition (3350-2632 A), both in the bound and predissociative regions. 19 The ' vr* band (2060-1820 A) corresponding to excitation of one of the second lone-pair electrons about oxygen is probably not excited to any significant extent because of relatively low intensity in this region. The results of simultaneous deposition and photolysis with the filtered Hg lamp (Table II, column 2), transmitting >3000 A, indicated new features at 2138, 1439, 1024, 866, and 863 cm"1; the first due to CO and the others due to cyclopropane.…”

Section: Resultsmentioning

confidence: 99%

Condensed-phase photochemistry of cyclobutanone

Thomas¹,

Guillory²

1974

J. Phys. Chem.

View full text Add to dashboard Cite

The ultraviolet and vacuum-ultraviolet photolyses of cyclobutanone (c-CsHeCO) in argon, carbon monoxide, and nitrogen matrices have been performed between 8 and 10 K. The results of these experiments suggest that the photodecomposition mechanism of cyclobutanone is a function of photon energy. The major products of photolysis observed are CO, c-CsHe, CH2CO, C2H4, and CsHg. These products result from at least two and possibly three primary photolysis processes: c-CsHeCO + hv -C2H4 + CH2CO (1); c-CsHeCO + hvc-CsH6 + CO (2), and possibly c-CsHgCO + hv -»• CsHe + CO (3). In process 2, propylene may also result from the isomerization of vibrationally excited cyclopropane, c-CsHe* * C3HÍ6 (2c), if it is not first quenched by the matrix, c-CsHg* + M -* c-CsHe + M (2b); where M is the matrix. No infrared detectable products were observed as a result of photolysis with a medium-pressure Hg lamp from exciting wavelengths above ~3100 Á. Photolysis into the predissociative region of the n ->• ir* (3350-2632 Á) band with the 3022-Á Hg line produced CO and c-CgHe only, while exposure to the full Hg arc with major lines at 3022, 2967, 2894, and 2804 Á resulted in infrared detectable products of CO, c-CsHe, CH2CO, and C3H6. Processes 1, 2, and possibly 3 are also the major reactions resulting from photolysis at 1745, 1634, 1580, and 1495 Á with various vacuum-ultraviolet resonance lamps, while no net photodecomposition or photoionization resulted at 1215 Á with a hydrogen resonance lamp. Based on relative intensities, the combination of processes 2 and 3 > 1 at all wavelengths employed in this study and (2c) and (3) are indistinguishable sources of CsHe. Although we obtained no direct evidence for the occurrence of (3) in this study nor have we been able to find any, we include its consideration because it is energically possible. Additional products obtained, due to secondary vacuum-ultraviolet photolysis below 1500 Á are methane, methylacetylene, aliene, and C20. The results from experiments using the CO matrix as a triplet quencher suggest that (2) may also proceed through ISC from the 1B2 state as observed for the first excited singlet, 1A2. A discussion of the photophysical and photochemical processes occurring as a function of specific electronic absorptions is presented. Some tentative vibrational assignments for the infrared frequencies of matrix-isolated cyclobutanone have also been made.

show abstract

Electronic Spectrum of Cyclobutanone

Cited by 30 publications

References 16 publications

Low Energy Electron Impact Ionization and Fragmentation: Cyclobutanone

Low Energy Electron Impact Ionization and Fragmentation: Cyclobutanone

Coherent Motion Reveals Non‐Ergodic Nature of Internal Conversion between Excited States

Condensed-phase photochemistry of cyclobutanone

Contact Info

Product

Resources

About