Bahman Solouki

Unstable intermediates in the gas-phase. Formation of thioformaldehyde from trithiolan

Pure thioformaldehyde H2CS in the gas phase is most conveniently prepared by heating 1,2,4-trithiolan to 840 K; the corresponding trithiolan 4-oxide yields a mixture of H2CS and H2CSO.

Gasphasen-Reaktionen, 35. Benzseleniren als kurzlebiges Zwischenprodukt in der Pyrolyse von 1.2.3-Benzoselenodiazol zu 6-Fulvenselon/ Benzselenirene as Short-lived Intermediate in the Pyrolysis of 1,2,3-Benzoselenodiazole to 6-Fulvenselone

Abstract In the pyrolysis of 1,2,3-benzoselenodiazole using a short-distance furnace, a short-lived intermediate is detected photoelectron spectroscopically. Mass spectra recorded under similar conditions suggest an isomer C6H4Se rearranging to the more stable final product 6-fulveneselone. The ionization pattern obtained by computerized spectra stripping is assigned to benzselenirene by molecular radical cation state comparison based on MNDO calculations.

Photoelektronen-Spektren und Moleküleigenschaften, LXIX [1, 2]. Moleküle mit S·̱·̱̱·̱·̱·̱̱·̱N-Mehrfachbindungen / Photoelectron Spectra and Molecular Properties, LXIX [1,2]. Molecules with S·̱·̱̱·̱·̱·̱̱·̱N Multiple Bonds

The He(I) photoelectron spectra of the following molecules with S·̱·̱̱·̱·̱·̱̱·̱N multiple bonds are assigned by radical cation state comparison between the chemically related compounds as well as by MO models based on CNDO calculations. From the ionisation energies of the O=S=O/HN=S=O pair a parameter απSN can be deduced, which proves to be useful in the discussion of other SN compounds like R3C-N=S=O and RN=S=NR.

Gas phase reactions.1,2FPS2 and FPS

The pyridinium betaine H5C5N·FPS2 dissociates at 770 K in the gas phase yielding the novel σ3λ5-phosphorane FPS2, which at 900 K splits off S2 to give FPS as substantiated by comparison with the photoelectron spectrum from its generation by Br2FPS debromination on silver wool above 800 K.