Three-dimensional organic cage with narrowband delayed fluorescence

Abstract

A new type of simple emissive organic cage consisting of diphenyl sulfone units and nitrogen atoms was developed via one-pot C–N coupling condensation or two-step reactions along with a series of sulfoxide cages obtained, which exhibited excellent chemical modifiability and structural stability. By precisely controlling the participation of donor and acceptor units, a highly soluble organic cage with delayed fluorescence was obtained for the first time. More interestingly, due to the restriction of intramolecular flipping by locking the building blocks within a rigid framework, this emissive organic cage further showed narrowband ultra-deep blue electroluminescence emission at 413 nm with a full-width at half-maximum of 35 nm. This finding not only expands the family of electroluminescent organic cages, but also opens up a new platform for delayed fluorescence materials with high solubility and color purity.