Erzeugung und Untersuchung des Cyclopentadienons mit der Methode der temperaturabhängigen Photoelektronenspektroskopie / Preparation and Investigation of Cyclopentadienone by Variable Temperature Photoelectron Spectroscopy (VTPES)

1978 ◽  
Vol 33 (3) ◽  
pp. 383-385 ◽  
Author(s):  
Veit Eck ◽  
Günther Lauer ◽  
Armin Schweig ◽  
Walter Thiel ◽  
Hans Vermeer

AbstractUsing our VTPES technique cyclopentadienone is generated in the gas phase at 500-600 °C from the three different precursors cyclobutene-3,4-dicarboxylic acid anhydride, o-phenylene sulfite and o-benzoquinone and its PE spectrum is recorded. The PE spectrum and also the PE spectra of the various precursors as well as of the cyclopentadienone dimer are interpreted on the basis of our recently developed PERTCI method (i. e. performing large scale perturbation configuration interaction calculations in connection with selection procedures). The agreement between measured and calculated ionization potentials is good.

2012 ◽  
Vol 403 ◽  
pp. 012019 ◽  
Author(s):  
Pieter Maris ◽  
H Metin Aktulga ◽  
Mark A Caprio ◽  
Ümit V Çatalyürek ◽  
Esmond G Ng ◽  
...  

1984 ◽  
Vol 39 (11) ◽  
pp. 1536-1540 ◽  
Author(s):  
Reinhard Schulz ◽  
Armin Schweig

Abstract The gas-phase pyrolysis of cyclohexeno-1,2,3-selenadiazole and cycloocteno-1,2,3-selenadiazole has been investigated by variable temperature photoelectron spectroscopy and matrix IR spectroscopy. The ring contracted, highly reactive products cyclopentylidenselenoketene (cyclopentylidenmethanselone) and cycloheptylidenselenoketene (cycloheptylidenmethanselone) - which had not been found in liquid phase thermolysis experiments - have been detected. Additionally HeI photoelectron and IR spectra of analogous ketenes and thioketenes are presented for comparative reasons.


1988 ◽  
Vol 66 (9) ◽  
pp. 2123-2129 ◽  
Author(s):  
I. B'Shary ◽  
C. Guimon ◽  
M. Grimaud ◽  
G. Pfister-Guillouzo ◽  
D. Liotard

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.


2013 ◽  
Vol 67 (1) ◽  
Author(s):  
Martin Danko ◽  
Matej Mičušík ◽  
Mária Omastová ◽  
Juraj Bujdák ◽  
Dušan Chorvát

AbstractNew fluorescence dyes with an alkoxysilane moiety were synthesised by the condensation of 3-(triethoxysilyl)-1-propanamine (3-aminopropyltriethoxysilane) with 4,10-benzothioxanthene-3,1′-dicarboxylic acid anhydride (BTXA) and N,N-dimethylaminonaphthalene-1,8-dicarboxylic acid anhydride (DMANA), which was accompanied by the formation of an imidic bridge. The compounds N-(3-(triethoxysilyl)propyl)-thioxantheno[2,1,9-dej]isoquinoline-1,3-dione (BTX-S) and 4-(N′, N′-dimethyl)-N-(triethoxysilyl)propyl-1,8-naphthalene dicarboxylic acid imide (DMAN-S) were characterised by steady-state and time-resolved fluorescence spectroscopy in chloroform and ethanol. Both conjugates (BTX-S and DMAN-S) exhibited absorption and emission bands in the same region as the un-substituted BTXA and DMANA. An important Stokes shift was observed for DMAN-S in ethanol. A high fluorescence quantum yield was observed for BTX-S in both solvents and for DMAN-S in chloroform. In addition, the newly developed fluorescent silane dyes were covalently attached to the microscopic particles of layered silicates and on the surface of SiO2 wafers as a proof of concept for fluorescence particle (surface) visualisation. The surface wafer modification was precisely characterised by X-ray photoelectron spectroscopy (XPS). Successful covalent linkage onto the particles of layered silicates was proved by confocal laser scanning microscopy technique.


2017 ◽  
Vol 95 (9) ◽  
pp. 878-883
Author(s):  
Franck Gilleron ◽  
Jean-Christophe Pain

We present a global approach that allows one to tackle cumbersome configuration–interaction calculations. The method is based on the use of approximate configuration-averaged Hamiltonian matrix elements that can be expressed in compact form as a combination of Slater integrals. With some assumptions, we show that the Hamiltonian matrix to be diagonalized may be reduced to a size equivalent to the number of configurations in the basis set. The approach can be used to estimate shifts of configuration average energies and changes in the total strength of transition arrays. The method is also well suited to work out roughly difficult configuration–interaction calculations, to determine the minimal set of interacting configurations to be used in actual fine-structure calculations.


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