X-Ray photoelectron spectroscopy of monosubstituted perfluorobenzenes

1977 ◽  
Vol 55 (8) ◽  
pp. 1279-1284 ◽  
Author(s):  
Barry C. Trudell ◽  
S. James W. Price
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
Photoelectron Spectra ◽  
Atomic Charges ◽  
X Ray ◽  
Sophisticated Analysis ◽  
Charge Calculations

The gas phase X-ray photoelectron spectra, XPS, were observed for the series C6F5X (X = F, Cl, I, Br, H). Binding energies were determined from the spectra using the ESCAPLOT Program. Charge calculations were carried out using Equalization of Electronegativity, CNDO/2, and ACHARGE approaches on each molecule. The more sophisticated analysis leads to the following equation correlating the (C 1s) binding energies and the atomic charges qi[Formula: see text]

X-ray photoelectron spectra of C6F5X compounds (X = CH3, CF3, CN, CHO, OH, OCH3, NH2, NO2)

1978 ◽  
Vol 56 (4) ◽  
pp. 538-542 ◽  
Author(s):  
Barry C. Trudell ◽  
S. James W. Price
Keyword(s):  
Gas Phase ◽  
Curve Fitting ◽  
Binding Energies ◽  
Photoelectron Spectra ◽  
Atomic Charges ◽  
X Ray ◽  
Wide Range ◽  
Charge Calculations

The gas phase photoelectron spectra, XPS, were observed for the series C6F5X (X = CH3, CF3, OCH3, OH, CHO, NO2, NH2, CN). Binding energies were determined from the spectra by using computer curve fitting. Charge calculations were carried out using CNDO/2 and ACHARGE techniques. The CNDO/2 analysis led to the following correlation for the C 1s binding energies and the atomic charges, qi[Formula: see text]Correlations were also obtained for O 1s and N 1s:[Formula: see text]These equations are based on only four and three points respectively. However, the N 1s values cover a wide range (Ei, 402 to 419 eV; qi, −0.2 to 0.5) and show a better correlation than those for oxygen.

Study of transition metal oxides by photoelectron spectroscopy

1979 ◽  
Vol 367 (1729) ◽  
pp. 239-252 ◽  
Keyword(s):  
Transition Metal Oxides ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Binding Energies ◽  
Photoelectron Spectra ◽  
Final State ◽  
Metal Insulator ◽  
X Ray ◽  
Valence States ◽  
Related Series

Systematics in the X-ray photoelectron spectra (X. p. e. s.) of Ti, V, Cr, Mn and Nb oxides with the metal ion in different oxidation states as well as of related series of mono-, sesqui- and di-oxides of the first row transi­tion metals have been investigated in detail. Core level binding energies, spin-orbit splittings and exchange splittings are found to exhibit inter­esting variations with the oxidation state of the metal or the nuclear charge The 3d binding energies of the monoxides show a proportionality to Goodenough’s ( R — R c ). Other aspects of interest in the study are the satellite structure and final state effects in the X. p. e. s. of the oxides, and identification of different valence states in oxides of the general formulae M n O 2 n -1 and M 3 O 4 . The nature of changes in the 3d bands of oxides under­-going metal-insulator transitions is also indicated.

The core binding energies of some gaseous aromatic carboxylic acids and their relationship to profon affinities and gas phase acidities

1988 ◽  
Vol 66 (8) ◽  
pp. 1919-1922 ◽  
Author(s):  
B. H. McQuaide ◽  
M. S. Banna
Keyword(s):  
Benzoic Acid ◽  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Carbonyl Oxygen ◽  
Binding Energies ◽  
Proton Affinities ◽  
Initial State ◽  
X Ray ◽  
Inductive Effects ◽  
Oxygen Ionization

The C 1s and O 1s core binding energies of gaseous benzoic, phthalic, isophthalic, and terephthalic acids have been measured by X-ray photoelectron spectroscopy. The π-donor relaxation energies associated with the carbonyl oxygen ionization in these systems have been found to be around 2 eV, close to the value for acetic acid. Comparison of the O 1s binding energies in phenol and benzoic acid with the gas phase acidities shows that the increased acidity of benzoic acid is attributable mostly to initial-state inductive effects. A number of O 1s – proton affinity correlations have been used to predict proton affinities for these acids. It is found that benzoic acid is the strongest base and the weakest acid.

N1s core binding energies for 2-, 3-, and 4-substituted pyridines determined by X-ray photoelectron spectroscopy. Correlations with theoretical models, substituent parameters, and gas phase basicities

1980 ◽  
Vol 58 (7) ◽  
pp. 694-703 ◽  
Author(s):  
R. S. Brown ◽  
A. Tse
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Chemical Shifts ◽  
Theoretical Models ◽  
Binding Energies ◽  
X Ray ◽  
Theoretical Approaches ◽  
Substituted Pyridines ◽  
Monosubstituted Benzenes ◽  
Gas Phase Basicities

N1s binding energies for 36 pyridines substituted at the 2-, 3-, and 4-positions have been determined by X-ray photoelectron spectroscopy. The differences in BE relative to pyridine are analysed in terms of existing theoretical approaches (electrostatic, ground potential, and relaxation potential models) and compared with [Formula: see text] values calculated for analogous monosubstituted benzenes. One finds good correlations of [Formula: see text] with solution determined σ-substituent values although some substituent values deviate from the correlation probably due to solution effects which are not present in the gas phase. Correlations between [Formula: see text] and 14N nmr chemical shifts are poor, particularly for electron withdrawing substituents. The relationship between [Formula: see text] and gas phase basicity values (ΔG0) is good, and it appears as if the [Formula: see text] is more sensitive to the substituent than ΔG0. MINDO/3 calculations on the methoxypyridines and their conjugate acids employing full geometry optimizations are presented and analysed in order to determine the effect of geometric relaxation on the gas phase basicity.

scholarly journals X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms

2015 ◽  
Vol 6 ◽  
pp. 177-192 ◽  
Author(s):  
Toma Susi ◽  
Thomas Pichler ◽  
Paola Ayala
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nanomaterials ◽  
Compositional Analysis ◽  
Binding Energies ◽  
Graphitic Carbon ◽  
Photoelectron Spectra ◽  
Intrinsic Properties ◽  
Important Work ◽  
X Ray ◽  
General Care

X-ray photoelectron spectroscopy (XPS) is one of the best tools for studying the chemical modification of surfaces, and in particular the distribution and bonding of heteroatom dopants in carbon nanomaterials such as graphene and carbon nanotubes. Although these materials have superb intrinsic properties, these often need to be modified in a controlled way for specific applications. Towards this aim, the most studied dopants are neighbors to carbon in the periodic table, nitrogen and boron, with phosphorus starting to emerge as an interesting new alternative. Hundreds of studies have used XPS for analyzing the concentration and bonding of dopants in various materials. Although the majority of works has concentrated on nitrogen, important work is still ongoing to identify its precise atomic bonding configurations. In general, care should be taken in the preparation of a suitable sample, consideration of the intrinsic photoemission response of the material in question, and the appropriate spectral analysis. If this is not the case, incorrect conclusions can easily be drawn, especially in the assignment of measured binding energies into specific atomic configurations. Starting from the characteristics of pristine materials, this review provides a practical guide for interpreting X-ray photoelectron spectra of doped graphitic carbon nanomaterials, and a reference for their binding energies that are vital for compositional analysis via XPS.

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.

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 .

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