Influence of H-bond competitors on the solvent-dependent structures of an octaurea-calix[4]tube.

ABSTRACT: A novel octaurea-calix[4]tube (UC4T) has been synthesized in three steps from the original Beer's p-tert-butylcalix[4]tube ionophore. In a polar solvent (DMSO-d₆), UC4T rapidly interconverts between two identical conformations with C_2v symmetry for the two calix[4]arene subunits. However, in a less polar solvent mixture (CDCl₃/DMSO-d₆, 98 : 2), UC4T adopts a highly distorted asymmetric structure, which hinders the formation of typical tetraurea calix[4]arene capsular assemblies. The complexation of potassium (or barium) cations inside the dioxyethylene ionophoric binding site of UC4T triggers a C_2v to C_4v symmetry rearrangement of the two calix[4]arene subunits. This rearrangement le

SUBMITTER: Milone M 

PROVIDER: S-EPMC10835760 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature