ChemInform Abstract: Applications of Photoelectron Spectroscopy to Molecular Properties. Part 35. Gas Phase Flash Pyrolysis of 3-Azido-1,2,4-triazole (I): Generation and UV Photoelectron Spectrum of N-Cyanomethanimine (II).

ChemInform ◽  
1989 ◽  
Vol 20 (10) ◽  
Author(s):  
I. B'SHARY ◽  
C. GUIMON ◽  
M. GRIMAUD ◽  
G. PFISTER-GUILLOUZO ◽  
D. LIOTARD
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectrum ◽  
Molecular Properties ◽  
Flash Pyrolysis

Gas phase flash pyrolysis of 3-azido-1,2,4-triazole: generation and ultraviolet photoelectron spectrum of N-cyanomethanimine

1988 ◽  
Vol 66 (9) ◽  
pp. 2123-2129 ◽  
Author(s):  
I. B'Shary ◽  
C. Guimon ◽  
M. Grimaud ◽  
G. Pfister-Guillouzo ◽  
D. Liotard
Keyword(s):  
Thermal Decomposition ◽  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectrum ◽  
Reaction Path ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Pyrolysis Gas ◽  
Flash Pyrolysis ◽  
Ionic States ◽  
Configuration Interaction Calculations

A dimer of HCN, N-cyanomethanimine 6, was prepared by flash pyrolysis (gas phase, 10−2 mbar) from 3-azido-1,2,4-triazole 1a and detected by ultraviolet photoelectron spectroscopy (HeI). Its ionization potentials were measured and the ionic states sequence proposed, with the aid of ab initio – CI (configuration interaction) calculations. The study of the MNDO potential hypersurface enabled us to propose a mechanism of the thermal reorganization of the precursor 1a. It is shown that the reaction path passes through the formation of the protomer 1b before thermal decomposition and the generation of the nitrene 2b.

scholarly journals Photoelectron spectroscopy of reactive intermediates

1988 ◽  
Vol 324 (1578) ◽  
pp. 197-207 ◽  
Keyword(s):  
Transition Metal ◽  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectrum ◽  
Reactive Intermediates ◽  
Vapour Phase ◽  
Photoelectron Spectra ◽  
Triatomic Molecule ◽  
Recent Developments ◽  
Vanadium Monoxide

Recent developments in the use of photoelectron spectroscopy to study reactive intermediates in the gas phase are reviewed. The information to be derived on low-lying cationic states from such studies is illustrated by considering two diatomic molecules, NCI and PF, and one triatomic molecule, HNO. Also, the use of a transition-metal photoelectron spectrum to interpret the photoelectron spectrum of the corresponding transition-metal oxide is discussed by using the spectra of vanadium and vanadium monoxide as examples. The value of super-heating in high-temperature photoelectron spectroscopy is demonstrated by considering the vapour-phase photoelectron spectra of the monomers and dimers of sodium hydroxide.

scholarly journals Thermolysis of 2,2-dimethoxy-5,5-dimethyl- Δ3- 1,3,4- oxadiazoline studied with photoelectron spectroscopy. He(I) photoelectron spectrum of dimethoxycarbene

1998 ◽  
Vol 76 (2) ◽  
pp. 238-240
Author(s):  
H M Muchall ◽  
N H Werstiuk ◽  
B Choudhury ◽  
J Ma ◽  
J Warkentin ◽  
...  
Keyword(s):  
Heat Source ◽  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectrum ◽  
Ionization Potentials ◽  
Perfect Agreement ◽  
Dimethyl Oxalate ◽  
Orbital Energies ◽  
Vertical Ionization Potentials ◽  
Experimental Values

Gas phase thermolysis of 2,2-dimethoxy-5,5-dimethyl- Δ3-1,3,4-oxadiazoline (1) in an ultraviolet photoelectron spectrometer by means of a CW CO2 laser as directed heat source at 26 W gave a complex PE spectrum that included ionization bands belonging to acetone, tetramethoxyethylene (3), and dimethyl oxalate (4). Subtraction of the spectra of acetone, 3, and 4 from the pyrolysis spectrum of 1 left a simple PE spectrum that is attributed to dimethoxycarbene (2) along with some ethane. ecke3LYP/6-31+G* calculations gave first adiabatic and vertical ionization potentials of 2 as well as orbital energies that are in perfect agreement with experimental values. From the available experimental and calculational data, 2 is assumed to adopt a w conformation.Key words: dimethoxycarbene, 2,2-dimethoxy- Δ3-1,3,4-oxadiazoline, tetramethoxyethylene, He(I) photoelectron spectroscopy, thermolysis.

scholarly journals Photoelektronen-Spektren und Moleküleigenschaften, LXIII Ionisierungsenergien von Phenyl-Methyl-Tellurid und Vergleich der Effekte von Sauerstoff-, Schwefel-, Selen- und Tellur-Substituenten auf das Benzol-π-System / Photoelectron Spectra and Molecular Properties, LXIII Ionization Energies of Phenyl Methyl Telluride and Comparison of Effects of Oxygen, Sulphur, Selenium and Tellurium Substituents on the Benzene π System

1976 ◽  
Vol 31 (12) ◽  
pp. 1611-1615 ◽  
Author(s):  
Galina Tschmutowa ◽  
Hans Bock
Keyword(s):  
Gas Phase ◽  
Dihedral Angle ◽  
Energy Region ◽  
Phenyl Ring ◽  
Photoelectron Spectrum ◽  
Lone Pair ◽  
Low Energy ◽  
Molecular Properties ◽  
Photoelectron Spectra ◽  
Overlapping Bands

The photoelectron spectrum of H5C6-Te-CH3 displays in its low energy region overlapping bands of gas-phase conformers. Depending on the dihedral angle between the plane of the phenyl ring and the tellurium lone pair, the π conjugation amounts to only 0.1 eV and 0.3 eV, respectively. These values are compared to the considerably larger ones found for the analogous phenyl derivatives H5C6-X-CH3 with X = O, S and Se.

Pyrolysis of 2-methoxy-5,5-dimethyl-2-methylthio- 2,5-dihydro[1,3,4]oxadiazole studied with photoelectron spectroscopy and DFT calculations — He(I) photoelectron spectrum of methoxy(methylthio)carbene

2006 ◽  
Vol 84 (4) ◽  
pp. 546-554 ◽  
Author(s):  
N H Werstiuk ◽  
A Klys ◽  
J Warkentin
Keyword(s):  
Heat Source ◽  
Dft Calculations ◽  
Key Words ◽  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Photoelectron Spectrum ◽  
Calculated Data ◽  
Experimental Results ◽  
Photoelectron Spectra ◽  
Key Words 2

Gas-phase pyrolysis of 2-methoxy-2-methylsulfanyl-5,5-dimethyl-2,5-dihydro[1,3,4]oxadiazole (1) (also known as 2-methoxy-5,5-dimethyl-2-methylthio-2,5-dihydro[1,3,4]oxadiazole and 2-methoxy-2-methylthio-5,5-dimethyl-Δ3-l,3,4-oxadiazoline) in the source of an UV photoelectron spectrometer, by means of a CW CO2 laser as directed heat source, gave a photoelectron (PE) spectrum that included ionization bands belonging to acetone and methoxy(methylthio)carbene (3). Photoelectron spectra of authentic samples of (E)-1,2-dimethoxy-1,2-dimethyl thioethene (4), (Z)-1,2-dimethoxy-1,2-dimethylthioethene (5), S-methyl thioethanoate (6), and O-methyl ethanethioate (7), which can be derived by dimerization and rearrangement of the carbene, established that these compounds are not present in the pyrolysate. DFT calculations at the B3PW91/6-31+G(d,p) level and simulation of PE spectra at the B3LYP/6-31+G(d,p) level were instrumental in the interpretation of the experimental results. From the available experimental and calculated data, 3 is formed in a Sickle conformation upon pyrolysis of 1. Transition states for the rearrangement of 3 were examined with QTAIM. Key words: 2-methoxy-5,5-dimethyl-2-methylthio-2,5-dihydro[1,3,4]oxadiazole, pyrolysis, He(I) photoelectron spectroscopy, methoxy(methylthio)carbene, DFT calculations, QTAIM.

Photoelectron Spectroscopy and Theoretical Study of AlnC5-/0 (n = 1-5) clusters: Structural Evolution, Relative Stability of Star-Like Cluster, and Planar Tetracoordinate Carbon Structure

2021 ◽  
Author(s):  
Chao-Jiang Zhang ◽  
Peng Wang ◽  
Xi-Ling Xu ◽  
Hong-Guang Xu ◽  
Weijun Zheng
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Relative Stability ◽  
Theoretical Study ◽  
Structural Evolution ◽  
Carbon Structure ◽  
Anion Photoelectron Spectroscopy

The AlnC5- (n = 1-5) clusters were detected in the gas-phase and were investigated by mass-selected anion photoelectron spectroscopy. The structures of AlnC5-/0 (n = 1-5) were explored by theoretical...

scholarly journals Dry Etching Performance and Gas-Phase Parameters of C6F12O + Ar Plasma in Comparison with CF4 + Ar

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1595
Author(s):  
Nomin Lim ◽  
Yeon Sik Choi ◽  
Alexander Efremov ◽  
Kwang-Ho Kwon
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Reactive Ion Etching ◽  
Research Work ◽  
Optical Emission ◽  
Plasma Parameters ◽  
Ion Etching ◽  
Ar Plasma ◽  
Ar Gas ◽  
Etching Selectivity

This research work deals with the comparative study of C6F12O + Ar and CF4 + Ar gas chemistries in respect to Si and SiO2 reactive-ion etching processes in a low power regime. Despite uncertain applicability of C6F12O as the fluorine-containing etchant gas, it is interesting because of the liquid (at room temperature) nature and weaker environmental impact (lower global warming potential). The combination of several experimental techniques (double Langmuir probe, optical emission spectroscopy, X-ray photoelectron spectroscopy) allowed one (a) to compare performances of given gas systems in respect to the reactive-ion etching of Si and SiO2; and (b) to associate the features of corresponding etching kinetics with those for gas-phase plasma parameters. It was found that both gas systems exhibit (a) similar changes in ion energy flux and F atom flux with variations on input RF power and gas pressure; (b) quite close polymerization abilities; and (c) identical behaviors of Si and SiO2 etching rates, as determined by the neutral-flux-limited regime of ion-assisted chemical reaction. Principal features of C6F12O + Ar plasma are only lower absolute etching rates (mainly due to the lower density and flux of F atoms) as well as some limitations in SiO2/Si etching selectivity.

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