Interlocking Organic Nanotubes into a Three-Dimensional Framework: Synthesis, Crystal Structure with Dual-Buckle Configuration, and Application in Stabilizing Lithium Metal Anode.

Single-crystalline organic nanotubes (ONTs) are very important to help us deeply understand the structure-property relationship, however, their preparation remains challenging. In this study, we propose a "B←N coordination-directed self-locking" strategy to construct robust single-crystalline ONTs (named as CityU-56). Single crystals of CityU-56 are assembled via the formation of dynamic B←N bonds between 2,2',7,7'-tetra(4-pyridyl)-9,9'-spirobifluorene (SPFPY) and 1,4-bis(benzodioxaborole)benzene (BACT). Single-crystal X-ray diffraction analysis indicates that CityU-56 possesses a well-defined prismatic nanotube structure with highly ordered arrays. Importantly, the dual buckle-tongue-latch interlocking mechanism between adjacent nanotubes stabilizes the ordered arrangement of the nanotubes through synergistic B←N coordination and π-π stacking. Given these advantages, CityU-56 has been demonstrated to serve as an artificial solid electrolyte interphase (ASEI) layer for lithium metal anodes, which significantly enhanced the stability and long-term cycling performance of the as-fabricated batteries.