Intrachannel vibronic coupling in molecular photoionization

2004 ◽  
Vol 82 (6) ◽  
pp. 1043-1051 ◽  
Author(s):  
G J Rathbone ◽  
E D Poliakoff ◽  
John D Bozek ◽  
R R Lucchese
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photoionization Cross Section ◽  
Vibronic Coupling ◽  
Photoelectron Spectra ◽  
Coupling Mechanism ◽  
Triatomic Molecules ◽  
Bending Mode ◽  
Stretching Vibration ◽  
Molecular Photoionization ◽  
Energy Dependent

We discuss the excitation of forbidden vibrational transitions accompanying photoionization of linear triatomic molecules. Excitation of a single quantum of the antisymmetric stretching vibration is observed for mole cules with inversion symmetry, as is the bending mode. Photoelectron spectra of the N2O+(A2Π), CO2+(C2Σg+), and CS2+(B2Σu+) states obtained over a range of ionization energies exhibit contrasting behavior for the relative intensities of the forbidden vibrations. These energy-dependent vibrational branching ratios are shown to result from an intrachannel vibronic coupling mechanism. Moreover, this intrachannel coupling can be further divided into two cases, one in which the photoionization cross section is sensitive to geometry changes, and a second case in which it is not. These different cases can be distinguished by comparing the experimental and theoretical results for all three molecules.Key words: photoelectron spectroscopy, vibronic coupling, photoionization.PACS Nos.: 33.60.Cv, 33.20.Ni, 33.20.Wr, 33.80.Eh

Study of Sulfur-Sulfur Nonbonded Interactions in Substituted Diphosphine Disulfides by Gas-Phase UV Photoelectron Spectroscopy

1981 ◽  
Vol 36 (1) ◽  
pp. 68-71
Author(s):  
Lucilla Alagna ◽  
Carla Cauletti ◽  
Marco Andreocci ◽  
Claudio Furlani ◽  
Gerhard Hagele
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectra ◽  
Coupling Mechanism ◽  
Nonbonded Interactions ◽  
Lone Pairs ◽  
Uv Photoelectron Spectroscopy

Ultraviolet photoelectron spectra (UPS) of tetrasubstituted diphosphine disulfides RR'P(S)- P(S)RR' exhibit peculiar 1:2:1 splitting patterns in the region 7.5-9.5 eV for which a throughbond coupling mechanism between the sulfur lone pairs lying in the PPS planes is proposed. Further bond orbitals are related to bands at higher I. E. in the UP spectra

A Discussion on photoelectron spectroscopy - Franck-Condon factors and autoionization in the photoelectron spectra of diatomic molecules

1970 ◽  
Vol 268 (1184) ◽  
pp. 159-162 ◽  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photoionization Cross Section ◽  
Resonance Wavelength ◽  
Exciting Radiation ◽  
Vibrational Structure ◽  
Photoelectron Spectra ◽  
Condon Factors ◽  
Franck Condon ◽  
Characteristic Manner ◽  
Good Agreement

Distributions of calculated Franck-Condon factors for autoionizing transitions are used to illustrate the way in which the vibrational structure of the photoelectron spectrum may be extended in a characteristic manner when the wavelength of the exciting radiation coincides with a resonance in the photoionization cross section of a diatomic gas. The calculations are found to be in good agreement with resonance wavelength photoelectron spectra from O2.

High Resolution Photoelectron Spectroscopy of Cryogenically-Cooled NO3ˉ

2019 ◽  
Author(s):  
Mark Babin ◽  
Jessalyn DeVine ◽  
John F. Stanton ◽  
Daniel Neumark ◽  
Martin DeWitt
Keyword(s):  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectra ◽  
Velocity Map Imaging ◽  
Vibrational Assignment ◽  
Neutral Radical ◽  
Resolution Measurement ◽  
Energy Dependent ◽  
Franck Condon ◽  
Insight Into

<p></p><p>High-resolution anion photoelectron spectra of cryogenically cooled NO<sub>3</sub>ˉ anions obtained using slow photoelectron velocity-map imaging are presented and provide new insight into the vibronic structure of the corresponding neutral radical. A combination of improved spectral resolution, measurement of energy-dependent intensity effects, temperature control, and comparison to theory allows for full assignment of the vibronic features observed in this spectrum. We obtain a refined electron affinity of 3.9289(14) eV for NO<sub>3</sub>. Further, the appearance of Franck-Condon forbidden transitions from vibrationally cold anions to neutral states with excitation along the NO<sub>3</sub> <i>v</i><sub>4</sub> mode confirms that these features arise from vibronic coupling with the excited state of NO<sub>3</sub> and are not hot bands as has been suggested. Together, the suite of experimental and simulated results provides clear evidence that the <i>v</i><sub>3</sub> fundamental of NO<sub>3</sub> resides near 1050 cm<sup>−1</sup>, addressing a long-standing controversy surrounding this vibrational assignment.</p> <p> </p><br><p></p>

High Resolution Photoelectron Spectroscopy of Cryogenically-Cooled NO3ˉ

2019 ◽  
Author(s):  
Mark Babin ◽  
Jessalyn DeVine ◽  
John F. Stanton ◽  
Daniel Neumark ◽  
Martin DeWitt
Keyword(s):  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectra ◽  
Velocity Map Imaging ◽  
Vibrational Assignment ◽  
Neutral Radical ◽  
Resolution Measurement ◽  
Energy Dependent ◽  
Franck Condon ◽  
Insight Into

<p></p><p>High-resolution anion photoelectron spectra of cryogenically cooled NO<sub>3</sub>ˉ anions obtained using slow photoelectron velocity-map imaging are presented and provide new insight into the vibronic structure of the corresponding neutral radical. A combination of improved spectral resolution, measurement of energy-dependent intensity effects, temperature control, and comparison to theory allows for full assignment of the vibronic features observed in this spectrum. We obtain a refined electron affinity of 3.9289(14) eV for NO<sub>3</sub>. Further, the appearance of Franck-Condon forbidden transitions from vibrationally cold anions to neutral states with excitation along the NO<sub>3</sub> <i>v</i><sub>4</sub> mode confirms that these features arise from vibronic coupling with the excited state of NO<sub>3</sub> and are not hot bands as has been suggested. Together, the suite of experimental and simulated results provides clear evidence that the <i>v</i><sub>3</sub> fundamental of NO<sub>3</sub> resides near 1050 cm<sup>−1</sup>, addressing a long-standing controversy surrounding this vibrational assignment.</p> <p> </p><br><p></p>

scholarly journals Modification of Wood with Monoethanolamino-borate by The Data of X-Ray Photoelectron Spectroscopy

2018 ◽  
Vol 196 ◽  
pp. 04005
Author(s):  
Irina Stepina ◽  
Irina Kotlyarova
Keyword(s):  
Particle Size ◽  
Photoelectron Spectroscopy ◽  
Model Compound ◽  
Hydrolytic Stability ◽  
Photoelectron Spectra ◽  
Wood Cellulose ◽  
Rapid Loss ◽  
X Ray ◽  
Wood Protection ◽  
Cellulose Materials

The difficulty of wood protection from biocorrosion and fire is due to the fact that modifiers in use are washed out from the surface of the substrate under the influence of environmental factors. This results in a rapid loss of the protective effect and other practically important wood characteristics caused by the modification. To solve this problem is the aim of our work. Here, monoethanolaminoborate is used as a modifier, where electron-donating nitrogen atom provides a coordination number equal to four to a boron atom, which determines the hydrolytic stability of the compounds formed. Alpha-cellulose ground mechanically to a particle size of 1 mm at most was used as a model compound for the modification. X-ray photoelectron spectra were recorded on the XSAM-800 spectrometer (Kratos, UK). Prolonged extraction of the modified samples preceded the registration of the photoelectron spectra to exclude the fixation of the modifier molecules unreacted with cellulose. As a result of the experiment, boron and nitrogen atoms were found in the modified substrate, which indicated the hydrolytic stability of the bonds formed between the modifier molecules and the substrate. Therefore monoethanolaminoborate can be considered as a non-extractable modifier for wood-cellulose materials.

scholarly journals Impact of high temperatures on aluminoceladonite studied by Mössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopy

2021 ◽  
Author(s):  
Mariola Kądziołka-Gaweł ◽  
Maria Czaja ◽  
Mateusz Dulski ◽  
Tomasz Krzykawski ◽  
Magdalena Szubka
Keyword(s):  
Photoelectron Spectroscopy ◽  
Integral Intensity ◽  
Photoelectron Spectra ◽  
X Ray Diffraction ◽  
Structural Reorganization ◽  
Oh Groups ◽  
X Ray ◽  
Al Content ◽  
Integral Intensity Ratio ◽  
Higher Temperature

AbstractMössbauer, Raman, X-ray diffraction and X-ray photoelectron spectroscopies were used to examine the effects of temperature on the structure of two aluminoceladonite samples. The process of oxidation of Fe2+ to Fe3+ ions started at about 350 °C for the sample richer in Al and at 300 °C for the sample somewhat lower Al-content. Mössbauer results show that this process may be associated with dehydroxylation or even initiate it. The first stage of dehydroxylation takes place at a temperature > 350 °C when the adjacent OH groups are replaced with a single residual oxygen atom. Up to ~500 °C, Fe ions do not migrate from cis-octahedra to trans-octahedra sites, but the coordination number of polyhedra changes from six to five. This temperature can be treated as the second stage of dehydroxylation. The temperature dependence on the integral intensity ratio between bands centered at ~590 and 705 cm−1 (I590/I705) clearly reflects the temperature at which six-coordinated polyhedra are transformed into five-coordinated polyhedra. X-ray photoelectron spectra obtained in the region of the Si2p, Al2p, Fe2p, K2p and O1s core levels, highlighted a route to identify the position of Si, Al, K and Fe cations in a structure of layered silicates with temperature. All the measurements show that the sample with a higher aluminum content and a lower iron content in octahedral sites starts to undergo a structural reorganization at a relatively higher temperature than the less aluminum-rich sample does. This suggests that iron may perform an important role in the initiation of the dehydroxylation of aluminoceladonites.

scholarly journals Photoelectron spectroscopy of the protoporphyrin IX dianion

2021 ◽  
Author(s):  
Jemma Gibbard ◽  
Connor Jack Clarke ◽  
Jan RR Verlet
Keyword(s):  
Photoelectron Spectroscopy ◽  
Femtosecond Lasers ◽  
Protoporphyrin Ix ◽  
Photoelectron Spectra ◽  
Two Dimensional

Two-dimensional photoelectron spectroscopy using nanosecond and femtosecond lasers has been used to study the Protopophyrin IX dianion at photon energies between 1.8 - 4.1 eV. The photoelectron spectra indicated the...

DEVELOPMENT OF A CONICAL ENERGY ANALYZER FOR ANGLE-RESOLVED PHOTOELECTRON SPECTROSCOPY

2002 ◽  
Vol 09 (01) ◽  
pp. 583-586
Author(s):  
KOTA IWASAKI ◽  
KOICHIRO MITSUKE
Keyword(s):  
Gas Phase ◽  
Energy Resolution ◽  
Photoelectron Spectroscopy ◽  
Angular Resolution ◽  
Photoelectron Spectra ◽  
Sensitive Detector ◽  
Energy Analyzer ◽  
Position Sensitive ◽  
Pass Energy ◽  
Helium Discharge

A new angle-resolving electron energy analyzer composed of a conical electrostatic prism and a position-sensitive detector was developed for gas phase photoelectron spectroscopy. The performance of the analyzer has been tested by measuring photoelectron spectra of Ar using a helium discharge lamp. The angular resolution of 3° was achieved at the pass energy E of 5.6 eV. The best energy resolution was ΔE/E = 0.043 at E = 1.4 eV .

Gas-Phase Tautomerism in the Triazoles and Tetrazoles: A Study by Photoelectron Spectroscopy and ab Initio Molecular Orbital Calculations

1981 ◽  
Vol 36 (11) ◽  
pp. 1246-1252 ◽  
Author(s):  
Michael H. Palmer ◽  
Isobel Simpson ◽  
J. Ross Wheeler
Keyword(s):  
Ab Initio ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Photoelectron Spectroscopy ◽  
Relative Stability ◽  
Photoelectron Spectra ◽  
Equilibrium Geometry ◽  
Molecular Orbital Calculations ◽  
Methyl Derivatives

The photoelectron spectra of the tautomeric 1,2,3,- and 1,2,4-triazole and 1,2,3,4-tetrazole systems have been compared with the corresponding N-methyl derivatives. The dominant tautomers in the gas phase have been identified as 2 H-1,2,3-triazole, 1 H-1,2,4-triazole and 2H-tetrazole.Full optimisation of the equilibrium geometry by ab initio molecular orbital methods leads to the same conclusions, for relative stability of the tautomers in each of the triazoles, but the calculations wrongly predict the tetrazole tautomerism.

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