Expanded Mercaptocalixarenes: A New Kind of Macrocyclic Ligands for Stabilization of Polynuclear Thiolate Clusters

Frederik Schleife , Clément Bonnot (1) , Jean-Claude Chambron (2) , Martin Börner , Berthold Kersting

1 ICMUB - Institut de Chimie Moléculaire de l'Université de Bourgogne [Dijon]
2 Institut de Chimie de Strasbourg

The syntheses and properties of expanded 4-tert-butyl-mercapto-calix[4]arenes, in which the methylene linkers are replaced by -CH2NRCH2- or -CH2NRCH2- and CH2NRCH2CH2CH2NRCH2- units, are described. The new macrocycles were obtained in a step-wise manner, utilizing fully protected, i.e. S-alkylated, derivatives of the oxidation-sensitive thiophenols in the cyclisation steps. Reductive cleavage of the macrobicyclic or macrotricyclic intermediates (6, 7, 11) afforded the free thiophenols (H48, H49, and H412) in preparative yields as their hydrochloride salts. The protected proligands can exist in two conformations, resembling the “cone” and “1,3-alternate” conformations found for the parent calix[4]arenes. The free macro-cycles do not show conformational isomerism, but are readily oxidized forming intramolecular disulfide linkages. Preliminary complexation experiments show that these expanded mercaptocalixarenes can serve as supporting ligands for tetranuclear thiolato clusters.

Domaines: Chimie

Frederik Schleife, Clément Bonnot, Jean-Claude Chambron, Martin Börner, Berthold Kersting. Expanded Mercaptocalixarenes: A New Kind of Macrocyclic Ligands for Stabilization of Polynuclear Thiolate Clusters. Chemistry - A European Journal, 2022, ⟨10.1002/chem.202104255⟩. ⟨hal-03852821⟩