The development of next‐generation molecular‐electronic, electrocatalytic, and energy‐storage systems depends on the availability of robust materials in which molecular charge‐storage sites and conductive hosts are in intimate contact. It is shown here that electron transfer from single‐walled carbon nanotubes (SWNTs) to polyoxometalate (POM) clusters results in the spontaneous formation of host–guest POM@SWNT redox‐active hybrid materials. The SWNTs can conduct charge to and from the encapsulated guest molecules, allowing electrical access to >90% of the encapsulated redox species. Furthermore, the SWNT hosts provide a physical barrier, protecting the POMs from chemical degradation during charging/discharging and facilitating efficient electron transfer throughout the composite, even in electrolytes that usually destroy POMs.

This is a repository copy of Atomic Mechanism of Metal Crystal Nucleus Formation in a Single-Walled Carbon Nanotube.

In organic synthesis, the composition and structure of products are predetermined by the reaction conditions; however, the synthesis of well-defined inorganic nanostructures often presents a significant challenge yielding non-stoichiometric or polymorphic products. In this study, confinement in the nanoscale cavities of single-walled carbon nanotubes (SWNT) provides a new approach for multi-step inorganic synthesis where sequential chemical transformations take place within the same nanotube. In the first step, SWNT donate electrons to the reactant iodine molecules (I2) transforming them to iodide anions (I -). These then react with metal hexacarbonyls (M(CO)6, M = Mo or W) in the next step yielding anionic nanoclusters [M6I14] 2-, the size and composition of which are strictly dictated by the nanotube cavity, as demonstrated by aberration corrected high resolution transmission electron microscopy (AC-HRTEM), scanning transmission electron microscopy (STEM) and energy dispersive X-ray (EDX) spectroscopy. Atoms in the nanoclusters [M6I14] 2-are arranged in a perfect octahedral geometry and can engage in further chemical reactions within the nanotube, either reacting with each other leading to a new polymeric phase of molybdenum iodide [Mo6I12]n, or with hydrogen sulphide gas giving rise to nanoribbons of molybdenum/tungsten disulphide [MS2]n in the third step of the synthesis. Electron microscopy measurements demonstrate that the products of the multi-step inorganic transformations are precisely controlled by the SWNT nanoreactor, with complementary Raman spectroscopy revealing the remarkable property of SWNT to act as a reservoir of electrons during the chemical transformation. The electron transfer from the hostnanotube to the reacting guest-molecules is essential for stabilising the anionic metal iodide 2 nanoclusters and for their further transformation to metal disulphide nanoribbons synthesised in the nanotubes in high yield.Keywords: Carbon Nanotube, Charge Transfer, Nanoparticle, Nanoreactor, Nanoribbon Single-walled carbon nanotubes (SWNT) are among the most effective and universal containers for molecules. Provided that the internal diameter of the host-nanotube is wider than the critical diameter of the guest-molecule, the insertion of molecules into SWNT is spontaneous and, in some cases, such as fullerenes and their derivatives, irreversible due to the ubiquitous van der Waals forces dominating the host guest interactions between the nanotube and molecules [1]. Fullerenes [2,3] or organic molecules [4][5][6][7][8][9][10] encapsulated in SWNT can then be triggered to react inside the nanotube to form unusual oligomers and polymers [11][12][13], graphene nanoribbons [14][15][16], nanotubes [8,17] or extraordinary molecular nanodiamonds [9]. These examples clearly demonstrate the use of SWNT as nanoscale chemical reactors, where the structure of the macromolecular product can be precisely controlled by spatial confinement of the reactions in the nanotube channel.In contrast to organic molecules,...

A high degree of crystallinity is an essential aspect in two-dimensional covalent organic frameworks, as many properties depend strongly on the structural arrangement of the different layers and their constituents. We introduce herein a new design strategy based on core-twisted polycyclic aromatic hydrocarbon as rigid nodes that give rise to a two-dimensional covalent organic framework with a wavy honeycomb (chair-like) lattice. The concave-convex self-complementarity of the wavy two-dimensional lattice guides the stacking of framework layers into a highly stable and ordered covalent organic framework that allows a full 3D analysis by transmission electron microscopy revealing its chair-like honeycomb facets and aligned mesoporous channels. Remarkably, the waviness of the framework does not disrupt the interlayer π-π stacking that shows charge transporting properties similar to those of planar covalent organic frameworks. The implementation of core-twisted aromatics as building blocks for covalent organic frameworks brings new possibilities in the design of highly ordered organic materials.

Catalysis of chemical reactions by nanosized clusters of transition metals holds the key to the provision of sustainable energy and materials. However, the atomistic behaviour of nanocatalysts still remains largely unknown due to uncertainties associated with the highly labile metal nanoclusters changing their structure during the reaction. In this study, we reveal and explore reactions of nm-sized clusters of 14 technologically important metals in carbon nano test tubes using time-series imaging by atomically-resolved transmission electron microscopy (TEM), employing the electron beam simultaneously as an imaging tool and stimulus of the reactions. Defect formation in nanotubes and growth of new structures promoted by metal nanoclusters enable the ranking of the different metals both in order of their bonding with carbon and their catalytic activity, showing significant variation across the Periodic Table of Elements. Metal nanoclusters exhibit complex dynamics shedding light on atomistic workings of nanocatalysts, with key features mirroring heterogeneous catalysis.