Thèse de doctorat : Université de Fribourg, 2003 ; no 1405.
During senescence, chlorophyll of higher plants is degraded into linear tetrapyrrolic catabolites. Their in vitro oxidation with chromic acid furnishes the constituting pyrrolic moieties as maleimides fragments. The substitution patterns of the isolated maleimides are related to the catabolites structures. All maleimides bear the characteristic methyl group of the former chlorophyll as well as a...
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In: Chemical Communications, 2005, vol. (33), p. 4155
Two diastereoisomers of tetranuclear cyclometallated iridium complexes, either having an inner core of HEXOL-type [Ir(IrCl₂)₃]⁶⁺ unit and a surface of six chiral, didentate, cyclometallated ligands, are stereoselectively synthesized from an enantiopure pinenopyridine derivative.
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Thèse de doctorat : Université de Fribourg, 2001 ; no 1332.
The first objective of this thesis is the calculation of excited state energies and properties of transition metal complexes using Density Functional Theory (DFT). To explore this wide topic, we did choose three different chemical systems. The first one, presented in the chapter 4, is about the photodissociation of the tris(2,2’- bipyridine)ruthenium(II) ([Ru(bpy)3]2+) ion. Over the last two...
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In: Chemistry - A European Journal, 2005, vol. 11, p. 185-194
Detailed protonation experiments of the [5,6]-pinenebipyridine molecule and the unsubstituted [4,5]- and [5,6]-CHIRAGEN[0] ligands in various solvents indicate a variety of structures of the protonated species. UV-visible and NMR measurements (including ¹⁵N chemical shifts) show the transition from trans to cis conformation of [5,6]-pinenebipyridine upon protonation. The...
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In: Dalton Transactions, 2004, vol. 3, p. 402-406
The enantiomerically pure chiral tris-chelating ligand (+)-(7S,10R)-L(L) comprising three 4,5-pinenobipyridine subunits connected through a mesityl spacer has been synthesized. Complexes of L with RuII and FeII have been prepared and characterised. NMR spectroscopy indicates that...
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In: Angewandte Chemie International Edition, 2004, vol. 43 (34), p. 4482-4485
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In: Helvetica Chimica Acta, 2005, vol. 88(3), p. 496-506
A publication by Alexander P. Smirnoff in Helvetica Chimica Acta in 1920 [6] describes the first synthesis of a coordination species, i.e., of tris(propane-1,2-diamine-κN¹,κN²)platinum(4+) ([PtIV(pn)₃]⁴⁺), where it was shown that the configuration of a chiral center in the ligand can influence the configuration at the metal. The present investigation of...
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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...
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In: Inorganica Chimica Acta, 2005, vol. 358(1), p. 41-49
A series of ligands, where two pinene-bipyridine moieties are either connected directly, or through a p-xylene bridge are investigated with respect to their complexation behaviour in solution. The bridged [5,6]-CHIRAGEN[p-xyl] ligands, which are substituted in 5' or 6' positions show self-assembly reactions, which lead to similar supramolecular species as the unsubstituted bis-pinene-bipyridines...
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Thèse de doctorat : Université de Fribourg, 2002 ; Nr. 1382.
Im Rahmen der vorliegenden Arbeit wurden neue enantiomerenreine 5’- und 6’- substituierte, mit Pinen annellierte Bipyridin- (Pinen-bpy Derivate) und N-Pyridin- Liganden (Pinen-N-py Derivate) hergestellt. Die 6’-Brom substituierten Pinen-bpy Derivate stellen dabei geeignete Zwischenstufen für die Synthese von weiteren 6’- substituierten Pinen-bpy Derivate dar. Tetradentate Liganden...
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