Molecular motion and bond dissociation are two of the most fundamental phenomena underpinning properties of molecular materials. We have entrapped HF and H2O molecules within the fullerene C60 cage, encapsulated within a single-walled carbon nanotube (X@C60)@SWNT where X = HF or H2O. (X@C60)@SWNT represents a class of molecular nanomaterial composed of a guest within a molecular host within a nanoscale host, enabling investigations of the interactions of isolated single di-or tri-atomic molecules with the electron beam. The use of the electron beam simultaneously as a stimulus of chemical reactions in molecules and as a sub-Å resolution imaging probe allows investigations of the molecular dynamics and reactivity in real time and at the atomic scale, which are probed directly by chromatic and spherical aberration corrected high resolution transmission electron microscopy (Cc/Cs-corrected HRTEM) imaging, or indirectly by vibrational electron energy loss spectroscopy (EELS) in situ during scanning transmission electron microscopy (STEM) experiments.Experimental measurements indicate that the electron beam triggers homolytic dissociation of the H-F or H-O bonds, respectively, causing the expulsion of the hydrogen atoms from the fullerene cage, leaving fluorine or oxygen behind. Due to a difference in the mechanisms of penetration 2 through the carbon lattice available for F or O atoms, atomic fluorine inside the fullerene cage appears to be more stable than the atomic oxygen under the same conditions. The use of (X@C60)@SWNT, where each molecule X is 'packaged' separately from each other, in combination with the electron microscopy methods and density functional theory (DFT) modelling in this work, enable bond dynamics and reactivity of individual atoms to be probed directly at the singlemolecule level.
We induce and study reactions of polyoxometalate (POM) molecules, [PW12O40]3− (Keggin) and [P2W18O62]6− (Wells–Dawson), at the single-molecule level, utilising TEM as an analytical tool, and nanotubes as test tubes.
We describe the preparation of hybrid redox materials based on polyoxomolybdates encapsulated within single‐walled carbon nanotubes (SWNTs). Polyoxomolybdates readily oxidize SWNTs under ambient conditions in solution, and here we study their charge‐transfer interactions with SWNTs to provide detailed mechanistic insights into the redox‐driven encapsulation of these and similar nanoclusters. We are able to correlate the relative redox potentials of the encapsulated clusters with the level of SWNT oxidation in the resultant hybrid materials and use this to show that precise redox tuning is a necessary requirement for successful encapsulation. The host–guest redox materials described here exhibit exceptional electrochemical stability, retaining up to 86 % of their charge capacity over 1000 oxidation/reduction cycles, despite the typical lability and solution‐phase electrochemical instability of the polyoxomolybdates we have explored. Our findings illustrate the broad applicability of the redox‐driven encapsulation approach to the design and fabrication of tunable, highly conductive, ultra‐stable nanoconfined energy materials.
Molecular magnetism and specifically magnetic molecules are recently gaining plenty of attention as key elements for quantum technologies, information processing, and spintronics. Transition to the nanoscale and implementation of ordered...
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