"Breathing" Motion of a Modulable Molecular Cavity.
A class of hemicryptophane cages that adopt imploded conformations in solution and in the solid state has been described and studied by NMR spectroscopy and X-ray crystallography. It is reported that the degree of collapse of the molecular cavity can be controlled by changing the stereochemistry of the chiral elements of the hemicryptophanes, leading to a modulation of their physical and chemical properties. Upon the binding of an oxidovanadium unit, the collapsed molecular cavity can inflate to give an expanded conformation. Removal of the vanadium core by an ancillary complexing ligand restores the initial folded structure. Thus, coordination/de-coordination of the metal ion controls the dynamic motions of the cage, leading to a reversible nanomechanical process. This controlled motion between a collapsed and expanded cavity can be seen as that of a breathable molecular cage.
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, 200062, Shanghai, P. R. China.|Laboratoire de Chimie, École Normale Supérieure de Lyon, CNRS, UCBL, 46 allée d'Italie, 69364, Lyon, France.
Dawei
D
Zhang
Laboratoire de Chimie, École Normale Supérieure de Lyon, CNRS, UCBL, 46 allée d'Italie, 69364, Lyon, France.
James Robert
JR
Cochrane
Laboratoire de Chimie, École Normale Supérieure de Lyon, CNRS, UCBL, 46 allée d'Italie, 69364, Lyon, France.
Sebastiano
S
Di Pietro
Laboratoire de Chimie, École Normale Supérieure de Lyon, CNRS, UCBL, 46 allée d'Italie, 69364, Lyon, France.
Laure
L
Guy
Laboratoire de Chimie de Coordination, CNRS, 205 Route de Narbonne, BP 44099, Université de Toulouse, UPS, INPT, 31077, Toulouse, Cedex 4, France.
Heinz
H
Gornitzka
Laboratoire de Chimie, École Normale Supérieure de Lyon, CNRS, UCBL, 46 allée d'Italie, 69364, Lyon, France.
Jean-Pierre
JP
Dutasta
Laboratoire de Chimie, École Normale Supérieure de Lyon, CNRS, UCBL, 46 allée d'Italie, 69364, Lyon, France.|Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France.
Alexandre
http://orcid.org/0000-0002-6745-5734
A
Martinez
chirality; hemicryptophane; imploded conformation; molecular cages; molecular switch