Evaluation of the stereoselectivity for titanium(IV)-based coordination entities induced by the enantiopure diphenylethene-1,2-diamine ligand
| Autor: | Marc Henry, Laurent Barloy, Pierre Mobian, Bruno Vincent, Nathalie Kyritsakas, Emilie Macker, Alain Chaumont |
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| Přispěvatelé: | Chimie de la matière complexe (CMC), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Strasbourg, Centre National de la Recherche Scientifique (CNRS)-Université Louis Pasteur - Strasbourg I-Institut de Chimie du CNRS (INC), Institut Le Bel, Université Louis Pasteur - Strasbourg I, Institut de recherche sur la biologie de l'insecte UMR7261 (IRBI), Université de Tours-Centre National de la Recherche Scientifique (CNRS), Départment de sciences économiques, Université de Montréal (UdeM), Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Denticity
010405 organic chemistry Ligand Diastereomer 010402 general chemistry 01 natural sciences 0104 chemical sciences Inorganic Chemistry chemistry.chemical_compound Crystallography Monomer Enantiopure drug chemistry Diamine Materials Chemistry Proton NMR Stereoselectivity [CHIM.COOR]Chemical Sciences/Coordination chemistry Physical and Theoretical Chemistry |
| Zdroj: | Inorganica Chimica Acta Inorganica Chimica Acta, Elsevier, 2019, 498, pp.119119. ⟨10.1016/j.ica.2019.119119⟩ |
| ISSN: | 0020-1693 |
| DOI: | 10.1016/j.ica.2019.119119⟩ |
| Popis: | International audience; This article describes the formation of neutral TiO 4 N 2-based coordination entities where the titanium centers are coordinated by oxygenated ligands incorporating one or two biphenolato units, i.e. L 1 and L 2 respectively. In these systems, the sixfold coordination spheres of each metallic center are completed by the enantiopure bi-dentate diphenylethene-1,2-diamine compound, abbreviated as dpeda. A solvent dependent diastereomeric ratio is evaluated by 1 H NMR for the monomeric [Ti(L 1) 2 ((1R,2R)-dpeda)] or [Ti(L 1) 2 ((1S,2S)-dpeda)] (abbreviated as [R-Ti] or [S-Ti] respectively) complexes. The highest diastereomeric ratio for [Ti(L 1) 2 (dpeda)] is obtained in chloroform (2 : 1). Energy calculation and circular dichroism spectra simulation, obtained by DFT, permit to assign the configuration of the stereoisomer formed in excess. The (1R,2R)-(+)-dpeda privileges the Δ form and (1S,2S)-(-)-dpeda the Λ form of the [Ti(L 1) 2 (dpeda)] stereoisomers. The helicates formulated as [Ti 2 (L 2) 2 ((1S,2S)-dpeda) 2 ] and [Ti 2 (L 2) 2 (1R,2R)-dpeda) 2 ] (abbreviated as [S-Ti2] or [R-Ti2] respectively) are obtained by following a multi-component self-assembly approach. In this case, the diastereomeric ratios evaluated by 1 H NMR are much lower compared to those determined for the monomeric species, and a privileged P and M configuration for the [Ti 2 (L 2) 2 (1R,2R)-dpeda) 2 ] helicate and the [Ti 2 (L 2) 2 ((1S,2S)-dpeda) 2 ] helicate respectively is assigned through theoretical calculations. Overall, this article describes a strategy to favour handedness in a helicate system where the chiral control is originated from a ligand that is not inscribed within the helical framework of the architecture. |
| Databáze: | OpenAIRE |
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