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Influence of exo-Adamantyl Groups and endo-OH Functions on the Threading of Calix[6]arene Macrocycle.

ABSTRACT: Calix[6]arenes bearing adamantyl groups at the exo-rim form pseudorotaxanes with dialkylammonium axles paired to the weakly coordinating [B(Ar^F)₄]^- anion. The exo-adamantyl groups give rise to a more efficient threading with respect to the exo-tert-butyl ones, leading to apparent association constants more than one order of magnitude higher. This improved stability has been ascribed to the more favorable van der Waals interactions of exo-adamantyls versus exo-tert-butyls with the cationic axle. Calix[6]arenes bearing endo-OH functions give rise to a less efficient threading with respect to the endo-OR ones, in line with what was known from the complexation of alkali metal cations.

SUBMITTER: Iuliano V

PROVIDER: S-EPMC8011915 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

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Influence of exo-Adamantyl Groups and endo-OH Functions on the Threading of Calix[6]arene Macrocycle.

Iuliano Veronica V Talotta Carmen C Gaeta Carmine C Hickey Neal N Geremia Silvano S Vatsouro Ivan I Kovalev Vladimir V Neri Placido P

The Journal of organic chemistry 20200921 19

Calix[6]arenes bearing adamantyl groups at the exo-rim form pseudorotaxanes with dialkylammonium axles paired to the weakly coordinating [B(ArF)4]- anion. The exo-adamantyl groups give rise to a more efficient threading with respect to the exo-tert-butyl ones, leading to apparent association constants more than one order of magnitude higher. This improved stability has been ascribed to the more favorable van der Waals interactions of < ...[more]

PMID: 32900204

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