1,3-Alternate Tetraamido-Azacalix[4]arenes as Selective Anion Receptors.
Gabriel CanardJudicaelle Andeme EdzangZhongrui ChenMatthieu ChesséMourad ElhabiriMichel GiorgiOlivier SiriPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2016)
Six tetraaza[1.1.1.1]cyclophane derivatives bearing peripheral amide groups were prepared according to two distinct synthetic strategies that depend on the connection pattern between the aryl units. NMR experiments combined with the X-ray structures of two tetraamide derivatives 4 b and 10 show that these cavitands adopt a 1,3-alternate conformation both in solution and in the solid state. Consequently, the four amide groups of the aza[1.1.1.1]-m,m,m,m-cyclophane isomer 10 can contribute to the same recognition process towards neutral water molecules or anion guests. NMR experiments, mass spectrometry analyses and single-crystal X-ray structures confirm the anion-binding ability of this receptor. Absorption spectrophotometric titrations in nonpolar solvents provided evidence for the selectivity of 10 to chloride anions in the halide series, with a corresponding association constant Ka reaching 2.5 × 10(6) m(-1).
Keyphrases
- solid state
- ionic liquid
- high resolution
- mass spectrometry
- dual energy
- liquid chromatography
- binding protein
- structure activity relationship
- computed tomography
- molecular dynamics simulations
- electron microscopy
- simultaneous determination
- magnetic resonance imaging
- capillary electrophoresis
- magnetic resonance
- crystal structure
- dna binding