“Breathing” Motion of a Modulable Molecular Cavity

Dawei Zhang (1, 2) , James Robert Cochrane (2) , Sebastiano Di pietro (2) , Laure Guy (2) , Heinz Gornitzka (3, 4) , Jean-Pierre Dutasta (2) , Alexandre Martinez (2, 5)

1 Shanghai Key Laboratory of Green Chemistry and Chemical Processes
2 LC - Laboratoire de Chimie - UMR5182
3 LCC - Laboratoire de chimie de coordination
4 UT3 - Université Toulouse III - Paul Sabatier
5 ISM2 - Institut des Sciences Moléculaires de Marseille

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. There is an increased interest in the synthesis and development of systems able to perform a defined function at the molecular level. [1] For instance, molecular machines can produce quasi-mechanical movements (output) in response to specific stimuli (input). Currently, synthetic systems mimicking the ability of brakes, [2a]

Domaines: Chimie

Dawei Zhang, James Robert Cochrane, Sebastiano Di pietro, Laure Guy, Heinz Gornitzka, et al.. “Breathing” Motion of a Modulable Molecular Cavity. Chemistry - A European Journal, 2017, 23 (27), pp.6495-6498. ⟨10.1002/chem.201700395⟩. ⟨hal-01682791⟩