Self-assembly of Ag(I) helicates with new enantiopure 5,6-Chiragen type ligands
- Mamula, Olimpia Institute of Chemical Technology, HES-SO Fribourg, Switzerland - Chemistry Department, University of Fribourg, Switzerland
- Bark, Thomas Chemistry Department, University of Fribourg, Switzerland
- Quinodoz, Boris Chemistry Department, University of Fribourg, Switzerland
- Stoeckli-Evans, Helen Institute of Physics, University of Neuchâtel, Switzerland
- Zelewsky, Alexander von Chemistry Department, University of Fribourg, Switzerland
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24.04.2018
Published in:
- Inorganica Chimica Acta. - 2018, vol. 475, p. 200–206
English
Two new chiral bis-bidentate, C2-symmetrical ligands belonging to the Chiragen family have been synthesised and characterised. They are designed for polynuclear self-assemblies since the two (−)-5,6-pinenebipyridines units are connected by bridges whose length and rigidity avoids the coordination of the bipyridine moieties to the same metal centre. The ligand L1 with a 1,4-dimethylene naphthalene bridge leads, by complexation with Ag(I) cations, to a polymeric, single stranded helix. The helical pitch contains five metal centers, two consecutive metal centers being connected by a bis-bidentate, helically wrapped ligand, one up and the other down resulting in a coordination number four. The chirality (Λ) around each metal centre is controlled by the six asymmetric carbons of the ligands and the homochirality of the metal centers gives rise to a P orientation at the helix level. The 1H-NMR measurements of these species in solution indicate a temperature dependent behaviour pointing out possible equilibria between various [AgnLn]n+ fragments as confirmed by MS-spectroscopy. The ligand L2 with a 4,4′-dimethylene-1,1′-biphenyl bridge reacts with Ag(I) and lead to well resolved and temperature independent 1H- NMR spectra suggesting the formation of a circular helicate.
- Faculty
- Faculté des sciences et de médecine
- Department
- Département de Chimie
- Language
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- English
- Classification
- Chemistry
- License
- License undefined
- Identifiers
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- RERO DOC 309440
- DOI 10.1016/j.ica.2017.09.003
- DOI 10.5517/ccdc.csd.cc1pbn1q
- Persistent URL
- https://folia.unifr.ch/unifr/documents/306695
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