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Molecular Rotors in a Metal-Organic Framework: Muons on a Hyper-Fast Carousel.

ABSTRACT: Using muon-spin spectroscopy, we study the exceptional dynamical properties of rotating molecular struts engineered within a Zn-based metal-organic framework at cryogenic temperatures, where the internal motions of almost any other organic substance are quenched. Muon-spin spectroscopy is particularly suited for this aim, as the experimental evidence suggests several implantation sites for the muons, among which at least one directly onto the rotating moiety. The dynamics of the molecular rotors are characterized by the exceptionally low activation energy E_A ∼ 30 cal mol^-1. At the same time, we evidence a highly unusual temperature dependence of the dipolar interaction of muons with nuclear magnetic moments on the rotors, suggesting a complex influence of the rotations on the muon implantation and diffusion.

SUBMITTER: Prando G

PROVIDER: S-EPMC8011913 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

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Molecular Rotors in a Metal-Organic Framework: Muons on a Hyper-Fast Carousel.

Prando Giacomo G Perego Jacopo J Negroni Mattia M Riccò Mauro M Bracco Silvia S Comotti Angiolina A Sozzani Piero P Carretta Pietro P

Nano letters 20200910 10

Using muon-spin spectroscopy, we study the exceptional dynamical properties of rotating molecular struts engineered within a Zn-based metal-organic framework at cryogenic temperatures, where the internal motions of almost any other organic substance are quenched. Muon-spin spectroscopy is particularly suited for this aim, as the experimental evidence suggests several implantation sites for the muons, among which at least one directly onto the rotating moiety. The dynamics of the molecular rotors ...[more]

PMID: 32870690

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