In: ChemBioChem, 2018, vol. 19, no. 9, p. 922–926
In nature, proteins serve as media for long‐distance electron transfer (ET) to carry out redox reactions in distant compartments. This ET occurs either by a single‐step superexchange or through a multi‐step charge hopping process, which uses side chains of amino acids as stepping stones. In this study we demonstrate that Phe can act as a relay amino acid for long‐distance electron...
|
In: The Journal of Organic Chemistry, 2016, vol. 81, no. 20, p. 9576–9584
High accuracy quantum chemical calculations show that the barriers to rotation of a CH2 group in the allyl cation, radical, and anion are 33, 14, and 21 kcal/mol, respectively. The benzyl cation, radical, and anion have barriers of 45, 11, and 24 kcal/mol, respectively. These barrier heights are related to the magnitude of the delocalization stabilization of each fully conjugated system. This...
|
In: CHIMIA International Journal for Chemistry, 2016, vol. 70, no. 3, p. 164–171
Radicalcations often undergo very unexpected rearrangements. Three examples of such rearrangements are given, and it is shown how vibronic coupling between the ground and low-lying excited states may cause certain bonds that are quite solid in the neutral molecules to become so weak that they break spontaneously, even though the bond order does not change (or changes very little) on...
|
In: The Journal of Organic Chemistry, 2011, vol. 76, no. 12, p. 4818–4830
The performance of 250 different computational protocols (combinations of density functionals, basis sets and methods) was assessed on a set of 165 well-established experimental ¹H–¹H nuclear coupling constants (JH–H) from 65 molecules spanning a wide range of “chemical space”. Thereby we found that, if one uses core-augmented basis sets and allows for linear scaling...
|
In: Angewandte Chemie International Edition, 2010, vol. 49, no. 2, p. 399-402
|
In: Chemistry - A European Journal, 2006, vol. 12(17), p. 4559-4567
Three tricyclic vinylcyclobutanes (3-methylenetricyclo[5.3.0.02,6]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...
|
In: Physical Chemistry Chemical Physics, 2006, vol. 8, p. 719-727
The photochemistry of p-azidoaniline was studied in argon matrices in the absence and presence of oxygen. With the help of quantum chemical calculations we were able to characterize the triplet p-aminophenylnitrene as well as the cis- and trans-p-aminophenylnitroso oxides. It was found that the latter two isomers can be interconverted by selective...
|
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...
|
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...
|
