Mechanically Interlocked Single‐Wall Carbon Nanotubes

Extensive research has been devoted to the chemical manipulation of carbon nanotubes. The attachment of molec- ular fragments through covalent-bond formation produces kinetically stable products, but implies the saturation of some of the CC double bonds of the nanotubes. Supramolecular modification maintains the structure of the SWNTs but yields labile species. Herein, we present a strategy for the synthesis of mechanically interlocked derivatives of SWNTs (MINTs). In the key rotaxane-forming step, we employed macrocycle precursors equipped with two p-extended tetrathiafulvalene SWNT recognition units and terminated with bisalkenes that were closed around the nanotubes through ring-closing meta- thesis (RCM). The mechanically interlocked nature of the derivatives was probed by analytical, spectroscopic, and microscopic techniques, as well as by appropriate control experiments. Individual macrocycles were observed by HR STEM to circumscribe the nanotubes. Ever since their discovery, (1) carbon nanotubes have remained in the spotlight of physical and chemical research owing to their outstanding physical properties. (2) However, the initial excitement about their possible application in the field of organic electronics has only recently started to become a reality. (3) The contribution of chemistry to carbon- nanotube science is focused on their synthesis, (4) and their covalent (5) or noncovalent (6) modification to attain specific electronic properties. The covalent modification of single-wall nanotubes (SWNTs) provides kinetically stable products, but implies the saturation of some of the CC double bonds of the nanotubes. The supramolecular modification of SWNTs enables conservation of the structure of the nanotubes, but in most cases the products lack kinetic stability. (7)