ZIF-8 is one of the most interesting metal-organic frameworks due to its high stability and unique capabilities for hydrocarbons separation. Its porous network is formed by large almost spherical cavities interconnected by very narrow windows, similar to 3.4 angstrom, which should be too small even for methane. At the same time the direct experimental observations show that ZIF-8 cavities are able to host even such large molecules as benzene. This effect is associated with the flexibility of the cavity widows, arising from dynamical freedom on the 2-methylimidazole (2-mIM) linkers that form the framework. In this work, by means of H-2 NMR we show that the 2-mIM linkers of the ZIF-8 are very mobile and their mobility is sensitive to the presence of benzene guest. In contrast with other known MOFs based on linearly bonded carboxylates, in guest-free ZIF-8 the plane of 2-mIM linker exhibits two-site flips within a sector of 2 phi(f) = 34 degrees with very low activation barrier (1.5 kJ mol(-1)) and high rates (similar to 10(12) s(-1)) Above 380 K the linkers begin to demonstrate additional fast librations with gradually increasing amplitudes gamma(lib) comparable with the two-site flips (gamma(lib) = +/- 17 degrees above 560 K). This is direct evidence that the ZIF-8 linkers twist notably, thus increasing the aperture of the windows sufficiently to fit very large molecules. Upon benzene loading, the geometry of the observed motions remains similar but the potential barrier of the linkers flipping rises up to 9 kJ mol(-1).
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Banerjee, Rahul
Phan, Anh
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Phan, Anh
Wang, Bo
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Wang, Bo
Knobler, Carolyn
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Knobler, Carolyn
Furukawa, Hiroyasu
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Furukawa, Hiroyasu
O'Keeffe, Michael
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Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
O'Keeffe, Michael
Yaghi, Omar M.
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
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Univ Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
Devautour-Vinot, Sabine
Diaby, Sekou
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Univ Cocody Abidjan, UFR SSMT, Chim Phys Lab, Abidjan, Cote IvoireUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
Diaby, Sekou
da Cunha, Denise
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Univ Versailles St Quentin En Yvelines, UMR CNRS 8180, Inst Lavoisier, F-78035 Versailles, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
da Cunha, Denise
Serre, Christian
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Univ Versailles St Quentin En Yvelines, UMR CNRS 8180, Inst Lavoisier, F-78035 Versailles, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
Serre, Christian
Horcajada, Patricia
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Univ Versailles St Quentin En Yvelines, UMR CNRS 8180, Inst Lavoisier, F-78035 Versailles, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
Horcajada, Patricia
Maurin, Guillaume
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Univ Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Banerjee, Rahul
Phan, Anh
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Phan, Anh
Wang, Bo
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Wang, Bo
Knobler, Carolyn
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Knobler, Carolyn
Furukawa, Hiroyasu
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
Furukawa, Hiroyasu
O'Keeffe, Michael
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Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
O'Keeffe, Michael
Yaghi, Omar M.
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Univ Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USAUniv Calif Los Angeles, Ctr Reticular Chem, Calif Nanosyst Inst, Dept Chem & Biochem, Los Angeles, CA 90095 USA
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Univ Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
Devautour-Vinot, Sabine
Diaby, Sekou
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Univ Cocody Abidjan, UFR SSMT, Chim Phys Lab, Abidjan, Cote IvoireUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
Diaby, Sekou
da Cunha, Denise
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机构:
Univ Versailles St Quentin En Yvelines, UMR CNRS 8180, Inst Lavoisier, F-78035 Versailles, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
da Cunha, Denise
Serre, Christian
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Univ Versailles St Quentin En Yvelines, UMR CNRS 8180, Inst Lavoisier, F-78035 Versailles, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
Serre, Christian
Horcajada, Patricia
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Univ Versailles St Quentin En Yvelines, UMR CNRS 8180, Inst Lavoisier, F-78035 Versailles, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France
Horcajada, Patricia
Maurin, Guillaume
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Univ Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, FranceUniv Montpellier 2, ENSCM, UMR CNRS 5253, Inst Charles Gerhardt Montpellier, F-34095 Montpellier 05, France