Combined gas electron diffraction and mass spectrometric experimental setup at Bielefeld University

2020 ◽  
Vol 91 (7) ◽  
pp. 073103
Author(s):  
Yury V. Vishnevskiy ◽  
Sebastian Blomeyer ◽  
Christian G. Reuter ◽  
Oleg A. Pimenov ◽  
Sergey A. Shlykov
2020 ◽  
Author(s):  
Yury Vishnevskiy ◽  
Sebastian Blomeyer ◽  
Christian G. Reuter

<div>Principles of low pressure gas electron diffraction(LPGED) are introduced. An experimental setup has</div><div>been constructed for measuring electron diffraction patterns of gaseous samples at pressures below 10−3</div><div>mbar. Test measurements have been performed for benzoic acid at T = 287 K corresponding to a vapor </div><div>pressure of the substance P = 2 × 10−4 mbar, for iodoform CHI3 at T = 288 K (P = 4 × 10−4 mbar) and for carbon tetraiodide CI4 at T = 290K (P = 1 × 10−4 mbar). Due to the low experimental temperature thermal decomposition of CI4 has been prevented, which was unavoidable in previous classical measurements at higher temperatures.</div><div>From the obtained data the molecular structures have been successfully refined. The most important</div><div>semi-empirical equilibrium molecular parameters are re(Car–Car)av = 1.387(5) Å in benzoic acid, re(C–I)</div><div>= 2.123(3) Å in iodoform and re(C–I) = 2.133(7) Å in carbon tetraiodide. The determined parameters</div><div>showed consistency with theoretically predicted values. A critical comparison with results of the earlier</div><div>investigations has also been done.</div>


1995 ◽  
Vol 344 (1-2) ◽  
pp. 127-134 ◽  
Author(s):  
Nina I. Giricheva ◽  
Georgii V. Girichev ◽  
Sergey A. Shlykov ◽  
Valentin A. Titov ◽  
Tamara P. Chusova

2020 ◽  
Author(s):  
Yury Vishnevskiy ◽  
Sebastian Blomeyer ◽  
Christian G. Reuter

<div>Principles of low pressure gas electron diffraction(LPGED) are introduced. An experimental setup has</div><div>been constructed for measuring electron diffraction patterns of gaseous samples at pressures below 10−3</div><div>mbar. Test measurements have been performed for benzoic acid at T = 287 K corresponding to a vapor </div><div>pressure of the substance P = 2 × 10−4 mbar, for iodoform CHI3 at T = 288 K (P = 4 × 10−4 mbar) and for carbon tetraiodide CI4 at T = 290K (P = 1 × 10−4 mbar). Due to the low experimental temperature thermal decomposition of CI4 has been prevented, which was unavoidable in previous classical measurements at higher temperatures.</div><div>From the obtained data the molecular structures have been successfully refined. The most important</div><div>semi-empirical equilibrium molecular parameters are re(Car–Car)av = 1.387(5) Å in benzoic acid, re(C–I)</div><div>= 2.123(3) Å in iodoform and re(C–I) = 2.133(7) Å in carbon tetraiodide. The determined parameters</div><div>showed consistency with theoretically predicted values. A critical comparison with results of the earlier</div><div>investigations has also been done.</div>


2020 ◽  
Author(s):  
Yury Vishnevskiy ◽  
Sebastian Blomeyer ◽  
Christian G. Reuter ◽  
Oleg A. Pimenov ◽  
Sergey A. Shlykov

We have designed and constructed a combined experimental setup for synchronous measurements of electron diffraction patterns and mass-spectra of gas samples. Test measurements have been performed for acetic acid at two temperatures, 296 and 457 K, respectively. Electron diffraction data have been analysed taking into account mass spectra measured in the same experiments. From the diffraction intensities molecular structures and mole fractions of the acetic acid monomer and dimer have been refined. The obtained results demonstrate the importance of measuring mass spectra in gas electron diffraction experiments. In particular, it is possible to detect the sample decomposition, which can be used for the optimization of experimental conditions and for the data interpretation. The determined in this work length of the hydrogen bond in the acetic acid dimer, re(O<sup>...</sup>H) = 1.657(9) Å, is in good agreement with modern theoretical predictions. We recommend to measure diffraction patterns of acetic acid for the calibration of the sample pressure in the diffraction point.<br>


2020 ◽  
Vol 91 (7) ◽  
pp. 074104
Author(s):  
Yury V. Vishnevskiy ◽  
Sebastian Blomeyer ◽  
Christian G. Reuter

2020 ◽  
Author(s):  
Yury Vishnevskiy ◽  
Sebastian Blomeyer ◽  
Christian G. Reuter ◽  
Oleg A. Pimenov ◽  
Sergey A. Shlykov

We have designed and constructed a combined experimental setup for synchronous measurements of electron diffraction patterns and mass-spectra of gas samples. Test measurements have been performed for acetic acid at two temperatures, 296 and 457 K, respectively. Electron diffraction data have been analysed taking into account mass spectra measured in the same experiments. From the diffraction intensities molecular structures and mole fractions of the acetic acid monomer and dimer have been refined. The obtained results demonstrate the importance of measuring mass spectra in gas electron diffraction experiments. In particular, it is possible to detect the sample decomposition, which can be used for the optimization of experimental conditions and for the data interpretation. The determined in this work length of the hydrogen bond in the acetic acid dimer, re(O<sup>...</sup>H) = 1.657(9) Å, is in good agreement with modern theoretical predictions. We recommend to measure diffraction patterns of acetic acid for the calibration of the sample pressure in the diffraction point.<br>


1985 ◽  
Vol 89 (15) ◽  
pp. 3298-3302 ◽  
Author(s):  
Satoshi Yamamoto ◽  
Munetaka Nakata ◽  
Tsutomu Fukuyama ◽  
Kozo Kuchitsu

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