Université de Fribourg

Photochemistry of reactive intermediates

Bally, Thomas

In: Chimia, 2007, vol. 61, no. 10, p. 645-649

This paper illustrates the research on the photochemistry of reactive intermediates that was (and still is) carried out in the author's research group on three typical examples: the photochemistry of arylcarbenes, arylnitrenes, and organic radical cations.

Université de Fribourg

Experimental and theoretical study of 2,6-difluorophenylnitrene, its radical cation, and their rearrangement products in argon matrices

Carra, Claudio ; Nussbaum, Rafael ; Bally, Thomas

In: ChemPhysChem, 2006, vol. 7(6), p. 1268-1275

2,6-Difluorophenylnitrene was reinvestigated both experimentally, in Ar matrices at 10 K, and computationally, by DFT and CASSCF/CASPT2 calculations. Almost-pure samples of both neutral rearrangement products (the bicyclic azirine and the cyclic ketenimine) of a phenylnitrene were prepared and characterized for the first time. These samples were then subjected to X-irradiation in the presence of...

Université de Fribourg

Radical Cations of Phenyl-Substituted Aziridines: What Are the Conditions for Ring Opening ?

Gaebert, Carsten ; Mattay, Jochen ; Toubartz, Marion ; Steenken, Steen ; Müller, Beat ; Bally, Thomas

In: Chemistry - A European Journal, 2005, vol. 11(4), p. 1294-1304

Radical cations were generated from different phenyl-substituted aziridines by pulse radiolysis in aqueous solution containing TlOH.+, N₃. or SO₄.- as oxidants or in n-butyl chloride, by ⁶⁰Co γ radiolysis in Freon matrices at 77 K, and in some cases by flash photolysis in aqueous solution. Depending on the substitution pattern of the aziridines, two...

Université de Fribourg

Oxidative rearrangements of tricyclic vinylcyclobutane derivatives

Grota, Juliane ; Mattay, Jochen ; Piech, Krzysztof ; Bally, Thomas

In: Chemistry - A European Journal, 2006, vol. 12(17), p. 4559-4567

Three tricyclic vinylcyclobutanes (3-methylenetricyclo[,6]decanes 1-3) have been subjected to ionization by photoinduced electron transfer in solution and by X-irradiation in Ar matrices. All three compounds undergo oxidative cycloreversion; the cleavage of the four-membered ring, however, occurs in a different direction depending on the presence of a methyl group...

Université de Fribourg

Electronic structure and absorption spectra of biferrocenyl and bisfulvalenide diiron radical cations: detection and assignment of new low-energy transitions

Warratz, Ralf ; Aboulfadl, Hanane ; Bally, Thomas ; Tuczek, Felix

In: Chemistry - A European Journal, 2009, vol. 15, no. 7, p. 1604 - 1617

Low-energy electronic transitions have been detected spectroscopically in the FeII-FeIII mixed-valent biferrocenyl radical cation, but are absent in the spectra of the neutral analogue. They have been assigned by time-dependent DFT calculations (squares in figure). Analogous investigations were performed for the bisfulvalenide FeII-FeIII radical cation....