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Template-Controlled Synthesis of Polyimidazolium Salts by Multiple [2+2] Cycloaddition Reactions.

ABSTRACT: The tetrakisimidazolium salt H4 -2(Br)4 , featuring a central benzene linker and 1,2,4,5-(nBu-imidazolium-Ph-CH=CH-) substituents reacts with Ag2 O in the presence of AgBF4 to yield the tetranuclear, oktakis-NHC assembly [3](BF4 )4 . Cation [3]4+ features four pairs of olefins from the two tetrakis-NHC ligands perfectly arranged for a subsequent [2+2] cycloaddition. Irradiation of [3](BF4 )4 with a high pressure Hg lamp connects the two tetra-NHC ligands through four cyclobutane linkers to give compound [4](BF4 )4 . Removal of the template metals yields the novel oktakisimidazolium salt H8 -5(BF4 )8 . The tetrakisimidazolium salt H4 -2(BF4 )4 and the oktakisimidazolium salt H8 -5(BF4 )8 have been used as multivalent anion receptors and their anion binding properties towards six different anions have been compared.

SUBMITTER: Dobbe CB

PROVIDER: S-EPMC7540564 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature

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Template-Controlled Synthesis of Polyimidazolium Salts by Multiple [2+2] Cycloaddition Reactions.

Dobbe Christian B CB Gutiérrez-Blanco Ana A Tan Tristan T Y TTY Hepp Alexander A Hepp Alexander A Poyatos Macarena M Peris Eduardo E Hahn F Ekkehardt FE

Chemistry (Weinheim an der Bergstrasse, Germany) 20200806 50

The tetrakisimidazolium salt H4 -2(Br)4 , featuring a central benzene linker and 1,2,4,5-(nBu-imidazolium-Ph-CH=CH-) substituents reacts with Ag2 O in the presence of AgBF4 to yield the tetranuclear, oktakis-NHC assembly [3](BF4 )4 . Cation [3]4+ features four pairs of olefins from the two tetrakis-NHC ligands perfectly arranged for a subsequent [2+2] cycloaddition. Irradiation of [3](BF4 )4 with a ...[more]

PMID: 32237240

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