Université de Fribourg

Electromers of the benzene dimer radical cation

Błoch-Mechkour, Anna ; Bally, Thomas

In: Physical Chemistry Chemical Physics, 2015, vol. 17, no. 16, p. 10624–10629

The well-studied benzene dimer radical cation, which is prototypical for this class of species, has been reinvestigated computationally. Thereby it turned out that both the σ-hemibonded and the half-shifted sandwich structures of the benzene dimer cation, which had been independently proposed, represent stationary points on the B2PLYP-D potential energy surfaces. However, these structures belong...

Université de Fribourg

Synthesis and rotation barriers in 2, 6-Di-(o-anisyl) anisole

Yamamoto, Takuhei ; Chen, Pi-Yu ; Lin, Guangxin ; Błoch-Mechkour, Anna ; Jacobsen, Neil E. ; Bally, Thomas ; Glass, Richard S.

In: Journal of Physical Organic Chemistry, 2012, p. -

Variable temperature ¹H NMR spectroscopic studies of 2, 6-di(o-anisyl) anisole show syn and anti atropisomers at low temperature. The barrier for interconverting these isomers by rotation about the aryl-aryl bond, found by fitting the experimental data, is 41.2 kJ/mol.

Université de Fribourg

Dimer radical cations of indole and indole-3-carbinol: localized and delocalized radical cations of diindolylmethane

Błoch-Mechkour, Anna ; Bally, Thomas ; Marcinek, Andrzej

In: The Journal of Physical Chemistry A, 2011, vol. 115, no. 26, p. 7700–7708

Extending our previous study on the title species (J. Phys. Chem. A2010, 114, 6787), we investigated the dimer cations that are formed on oxidation of the glucobrassin derivatives indole-3-carbinol (I3C) and diindolylmethane (DIM) and of parent indole (I). Radiolysis in ionic liquid and Ar matrices shows that, at sufficiently high concentrations and/or on...

Université de Fribourg

Synthesis and structure of m-terphenyl thio-, seleno-, and telluroethers

Zakai, Uzma I. ; Błoch-Mechkour, Anna ; Jacobsen, Neil E. ; Abrell, Leif ; Lin, Guangxin ; Nichol, Gary S. ; Bally, Thomas ; Glass, Richard S.

In: Journal of Organic Chemistry, 2011, vol. 75, no. 24, p. 8363–8371

Several routes for the synthesis of m-terphenyl thio-, seleno-, and telluroethers were investigated. m-Terphenyl iodides react with diphenyl diselenides or ditellurides (CsOH·H₂O, DMSO, 110 °C) to give the desired compounds in 19−84% yield which significantly extends the previously reported such reactions because o-benzyne cannot be an intermediate as previously...

Université de Fribourg

Radicals and radical ions derived from indole, indole-3-carbinol and diindolylmethane

Błoch-Mechkour, Anna ; Bally, Thomas ; Sikora, Adam ; Michalski, Radosław ; Marcinek, Andrzej ; Gębicki, Jerzy

In: The Journal of Physical Chemistry A, 2010, vol. 114, no. 25, p. 6787–6794

The primary products, i.e., the radical cations and radicals obtained on oxidation of the glucobrassicin metabolites (and dietary supplements), indole-3-carbinol (I3C) and diindolylmethane (DIM), and those from parent indole (I) are characterized in an ionic liquid and in Ar matrices. The radical cations of I and I3C are stable toward (photo)deprotonation under these conditions, but the resulting...