Soluble metal-oxide frameworks: Transport of large organic guests through smaller subnanoscale pores and the effects of nano-confinement on hydrophobic self-assembly and organic reactions
Zusammenfassung der Projektergebnisse
Using a “capsule”-like molybdenum-oxide-based framework as a soluble analog of porous solid-state (rigid) oxides, we recently reported a new phenomenon: the passage of branched-alkane “guests” through flexible sub-nanometer Mo9O9 apertures whose geometrical diameters are smaller than the entering species. This new phenomenon, reflecting the greater flexibility of molecular versus solid-state structures, represented a distinct departure from traditional models for diffusion through rigid porous solid-oxides. Continuing that line of research, we reported on confinement effects and uptake-release equilibria associated with the formation of a spherical 24 butyrate aggregate with a hydrophobic cavity. Since start of the herein-reported DFG-sponsored program in 2011, we have not only investigated fundamental mechanism(s) responsible for the uptake of large guests, and of the coupling of uptake/release equilibria to translocations of guests within the capsule, but have demonstrated new phenomena related to two important and entirely different areas of fundamental science described in our original DFG application. First, metal-oxide capsules were used as “nano-reactors” for catalysis which, in an unprecedented fashion, involved “Activation by Regulated Access to Sixty Metal Centers Spanning a Truncated Icosahedron”. In parallel with that work, the unique properties of the nano-capsule - including options for rational modification of its internal environment - were used to provide the first stepwise observation of hydrophobic self-assembly. Four publications of this project have been highlighted by internationally recognized science writers.
Projektbezogene Publikationen (Auswahl)
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Guests on different internal capsule sites exchange with each other and with the outside. Angew. Chem. Int. Ed. 50, 410-414 (2011)
O. A. Petina, D. Rehder, E. T. K. Haupt, A. Grego, I. A. Weinstock, A. Merca, H. Bögge, J. Szakacs, A. Müller
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Pore and interior properties of a metal-oxide-based capsule softened: Substituting 60 oxide by 60 sulfide ligands. Angew. Chem. Int. Ed. 50, 12326 –12329 (2011)
C. Schäffer, A. M. Todea, H. Bögge, E. Cadot, P. Gouzerh, S. Kopilevich, I. A. Weinstock, A. Müller
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Catalysis in a porous molecular capsule: Activation by regulated access to sixty metal centers spanning a truncated icosahedron. J. Am. Chem. Soc. 134, 13082-13088 (2012)
S. Kopilevich, A. Gil, M. Garcia-Ratés, J. B. Avalos, C. Bo, A. Müller, I. A. Weinstock
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Stepwise-resolved thermodynamics of hydrophobic self-assembly. Angew. Chem. Int. Ed. 52, 8358-8362 (2013)
A. Grego, A. Müller, I. A. Weinstock
