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Süss-Fink, Georg
Nom
Süss-Fink, Georg
Affiliation principale
Fonction
Professeur ordinaire
Email
georg.suess-fink@unine.ch
Identifiants
Résultat de la recherche
Voici les éléments 1 - 6 sur 6
- PublicationAccès libreSelf-assembled chloro-bridged metallo-prismatic cations of the general formula [M6 (η5-C5Me5)6 (μ3-tpt)2 (μ-Cl)6]6+ (M = Rh, Ir; tpt = 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine)(2007)
; Two cationic pentamethylcyclopentadienyl metal-based hexanuclear complexes with trigonal prismatic architecture have been synthesised through a two-step strategy. The dinuclear complexes [M(η5- C5Me5)(μ-Cl)Cl]2 (M = rhodium and iridium) react with 2,4,6-tri(pyridin-4-yl)-1,3,5-triazine (tpt) in dichloromethane to give the trinuclear complexes [Rh3 (η5-C5Me5)3 (μ3-tpt)Cl6] (1) and [Ir3(η5-C5Me5)3 (μ3-tpt)Cl6] (2), respectively. Addition of silver triflate to 1 and 2 in dichloromethane connects two identical triangular panels to form the hexanuclear metallo-prismatic cations [Rh6 (η5-C5Me5)6 (μ3-tpt)2 (μ-Cl)6]6+ (3) and [Ir6 (η5-C5Me5)6 (μ3-tpt)2 (μ-Cl)6]6+ (4), respectively. Cations 3 and 4 have been isolated as their triflate salts and characterised by 1H NMR, IR and UV/visible spectroscopy. - PublicationMétadonnées seulementNew aryl phosphinite ligands avoiding ortho-metallation: Synthesis and molecular structures of trans-[PdCl2(PPh2OR)(2)] and trans-[Rh(CO)Cl(PPh2OR)(2)] (R=2,4,6-Me3C6H2; 2,6-Ph2C6H3)(2005)
- PublicationAccès libreNew aryl phosphinite ligands avoiding ortho-metallation: Synthesis and molecular structures of trans-[PdCl2(PPh2OR)2] and trans-[Rh(CO)Cl(PPh2OR) 2] (R = 2,4,6-Me3C6H2; 2,6-Ph2C6H3)(2005)
- PublicationAccès libreAn iterative strategy for the synthesis of oligothiophenes by catalytic cross-coupling reactions(2004)
; ; An iterative strategy for the synthesis of new sulfur-functionalized oligothiophenes by Suzuki or Stille cross-coupling reactions was applied to the reaction of 4-bromo-tert-butylphenylthioether with thiophene derivatives. The planarity of the oligothiophenes obtained was confirmed by the single-crystal X-ray structure analysis of 2-(4-tert-butylthiophenyl)thiophene, which shows a potentially large electronic conjugation length. - PublicationAccès libreNew Diphosphine Ligands Containing Ethyleneglycol and Amino Alcohol Spacers for the Rhodium-Catalyzed Carbonylation of Methanol(2002)
; ; The new diphosphine ligands Ph2PC6H4C(O)X(CH2)2OC(O)C6H4PPh2 (1: X=NH; 2: X=NPh; 3: X=O) and Ph2PC6H4C(O)O(CH2)2O(CH2)2OC(O)C6H4PPh2 (5) as well as the monophosphine ligand Ph2PC6H4C(O)X(CH2)2OH (4) have been prepared from 2-diphenylphosphinobenzoic acid and the corresponding amino alcohols or diols. Coordination of the diphosphine ligands to rhodium, iridium, and platinum resulted in the formation of the square-planar complexes [(PP)Rh(CO)Cl] (6: PP=1; 7: PP=2; 8: PP=3), [(PP)Rh(CO)Cl]2 (9: PP=5), [(P-P)Ir(cod)Cl] (10: PP=1; 11: PP=2; 12: PP=3), [(PP)Ir(CO)Cl] (13: PP=1; 14: PP=2; 15: PP=3), and [(PP)PtI2] (18: PP=2). In all complexes, the diphosphine ligands are trans coordinated to the metal center, thanks to the large spacer groups, which allow the two phosphorus atoms to occupy opposite positions in the square-planar coordination geometry. The trans coordination is demonstrated unambiguously by the single-crystal X-ray structure analysis of complex 18. In the case of the diphosphine ligand 5, the spacer group is so large that dinuclear complexes with ligand 5 in bridging positions are formed, maintaining the trans coordination of the P atoms on each metal center, as shown by the crystal structure analysis of 9. The monophosphine ligand 4 reacts with [{Ir(cod)Cl}2] (cod=cyclooctadiene) to give the simple derivative [(4)Ir(cod)Cl] (16) which is converted into the carbonyl complex [(4)Ir(CO)2Cl] (17) with carbon monoxide. The crystal structure analysis of 16 also reveals a square-planar coordination geometry in which the phosphine ligand occupies a position cis with respect to the chloro ligand. The diphosphine ligands 1, 2, 3, and 5 have been tested as cocatalysts in combination with the catalyst precursors [{Rh(CO)2Cl}2] and [{Ir(cod)Cl}2] or [H2IrCl6] for the carbonylation of methanol at 170 °C and 22 bar CO. The best results (TON 800 after 15 min) are obtained for the combination 2/[{Rh(CO)2Cl}2]. After the catalytic reaction, complex 7 is identified in the reaction mixture and can be isolated; it is active for further runs without loss of catalytic activity. - PublicationAccès libreDendritic Systems Based on Dinuclear Ruthenium or Rhodium Units Generating Peripheral Catalytic Sites(2002)
; Nous avons synthétisé et caractérisé les nouveaux cations dendritiques 1-4 contenant les unités Ru2S3 ou Rh2S3. L'analyse de la structure aux rayons X de 2-Cl montre un coeur Rh2S3à géométrie bipyramide trigonale. La réaction des groupements OH périphériques avec l'acide 2-diphénylphosphinobenzoïque permet la formation des cations dendritiques 5-8 fonctionnalisés par des phosphines. Le cation 5 qui contient deux atomes de ruthénium au centre et trois fonctions PPh2 à la périphérie peut servir de ligand avec le rhodium(I) et permettre d'augmenter significativement l'activité catalytique du précurseur [{Rh(CO)2Cl}2] pour la carbonylation du méthanol., A series of dendritic cations 1-4 containing Ru2S3 or Rh2S3 units, either in the core or in the dendrons, has been synthesized and characterized. The X-ray crystal structure analysis of 2-Cl shows a trigonal bipyramidal Rh2S3 core with propeller-like para-hydroxyphenyl substituents at the sulfur atoms. Reaction of the peripheral OH groups with diphenylphosphino benzoic acid results in the formation of phosphine-functionalized dendritic cations 5-8. The ruthenium-containing cation 5, with three PPh2 functions at the periphery, acts as ligand for rhodium(I) and enhances significantly the catalytic activity of [{Rh(CO)2Cl}2] for the carbonylation of methanol.