Université de Fribourg

Magnetic anisotropy in ‘scorpionate’ first-row transition-metal complexes: a theoretical investigation

Perić, Marko ; García-Fuente, Amador ; Zlatar, Matija ; Daul, Claude ; Stepanović, Stepan ; García-Fernández, Pablo ; Gruden-Pavlović, Maja

In: Chemistry – A European Journal, 2015, vol. 21, no. 9, p. 3716–3726

In this work we have analyzed in detail the magnetic anisotropy in a series of hydrotris(pyrazolyl)borate (Tp−) metal complexes, namely [VTpCl]+, [CrTpCl]+, [MnTpCl]+, [FeTpCl], [CoTpCl], and [NiTpCl], and their substituted methyl and tert-butyl analogues with the goal of observing the effect of the ligand field on the magnetic properties. In the [VTpCl]+, [CrTpCl]+, [CoTpCl], and [NiTpCl]...

Université de Fribourg

pH-dependent coordination of AgI ions by histidine: experiment, theory, and a model for SilE

Mirolo, Laurent ; Schmidt, Tobias ; Eckhardt, Sonja ; Meuwly, Markus ; Fromm, Katharina M.

In: Chemistry - A European Journal, 2013, vol. 19, no. 5, p. 1754–1761

Artificial implants and biomaterials lack the natural defense system of our body and, thus, have to be protected from bacterial adhesion and biofilm formation. In addition to the increasing number of implanted objects, the resistance of bacteria is also an important problem. Silver ions are well-known for their antimicrobial properties, yet not a lot is known about their mode of action. Silver is...

Université de Fribourg

Polytopal rearrangement of [Ni(acac)₂(py)]: A new square pyramid ⇄ trigonal bipyramid twist mechanism

Daul, Claude ; Niketic, Svetozar ; Rauzy, Cédrick ; Schläpfer, Carl-Wilhelm

In: Chemistry - A European Journal, 2004, vol. 10(3), p. 721-727

The interconversion mechanisms between three idealized polytopal forms (a square pyramid and two trigonal bipyramids) of [M(bidentate)₂(unidentate)] were investigated by an original combination of molecular mechanics (MM) and density functional theory (DFT) approaches. MM was used to model the mechanistic rearrangement path, and DFT to study selected points along this path. The test case was a...

Université de Fribourg

Synthesis and Stereochemical Properties of Chiral Square Complexes of Iron(II)

Bark, Thomas ; Zelewsky, Alexander von ; Rappoport, Dmitrij ; Neuburger, Markus ; Schaffner, Silvia ; Lacour, Jérôme ; Jodry, Jonathan

In: Chemistry - A European Journal, 2004, vol. 10(19), p. 4839-4845

Der hexadentate und ditopische Ligand 2,5-Bis([2,2']bipyridin-6-yl)pyrazin bildet bei der Selbstorganisationsreaktion mit Fe²⁺-Ionen einen chiralen, quadratförmigen Tetramerkomplex. Das Racemat dieses Komplexes wurde mit Hilfe von Antimonyltartrat in die Enantiomere getrennt. Die Reinheit des Enantiomers wurde durch NMR-Spektroskopie unter Zuhilfenahme eines chiralen, diamagnetischen...

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...