249
Multivalent Crown-ether Receptors Enable Allosteric Regulation of Anion Exchange in an Fe4L6 Tetrahedron

L.K.S. von Krbek, D.A. Roberts, B.S. Pilgrim, C.A. Schalley, J.R. Nitschke – 2018

Precise control over guest uptake and release in molecular cages is critical for applications in catalysis and chemical separations. Here we report a strategy for regulating the rate of internally-bound anion exchange within an FeII4L6 metal-organic tetrahedron through external coordination of tripodal tris(alkylammonium) cations. The cage features three flexible 18-crown-6 receptors at each of its FeII vertices, facilitating strong tritopic interactions with tris(ammonium) cations to ‘cap’ the vertices of the tetrahedron. This vertex-capping mechanism restricts the flexibility of the cage framework, which reduces the rate of anion exchange within its central cavity 20-fold when tris(ammonium) cations are bound externally. Thus, we demonstrate the use of an externally-bound multivalent effector for allosteric control over internal guest binding in a molecular cage.

Title
249
Multivalent Crown-ether Receptors Enable Allosteric Regulation of Anion Exchange in an Fe4L6 Tetrahedron
Author
L.K.S. von Krbek, D.A. Roberts, B.S. Pilgrim, C.A. Schalley, J.R. Nitschke
Date
2018-09-03
Identifier
DOI: 10.1002/anie.201808534
Citation
Angew. Chem. Int. Ed. 2018, 57, 14121-14124; Angew. Chem. 2018, 130, 14317-14320
Type
Text