Highly emissive tribenzotriquinacene-based double-rimed nanocube

The study of discrete nanosized cages has gone a long way to seek aesthetically appealing structures and to carry out functional applications. Although the construction of supramolecular cages via a bottom-up self-assembly process has been well developed, the sophisticated synthesis still remains a challenge. Here we report the design and assembly of a giant double-rimed nanocube Zn₂₄LH₈, built with 8 tribenzotriquinacene as six-connected vertices and 24 <tpy-Zn²⁺-tpy> (tpy = terpyridine) connectivities serving as the edges. From the single-crystal structure of tribenzotriquinacene-based ligand LH, the bowl-shaped ligand defines a suitable rigid platform for the spatially well-defined attachment of three sets of parallel vertices, which promotes the quantitative formation of the desired three-dimensional (3D) double-rimed cubic architectures. The formed nanocube Zn₂₄LH₈ possesses molecular weight up to 25.6 kDa and side length 5.3 nm. Remarkably, the Zn₂₄LH₈ exhibits strong cyan light emission with high luminescence quantum yields in solution and in the solid state based on the inherent cage-confinement induced emission enhancement. By adding orange-emissive Rhodamine B, emission tuning experiments were achieved including white light emission. This work presents a new system for the imitation of complex assemblies and provides a promising candidate for emissive materials. [Figure not available: see fulltext.]