Stereospecific redox-mediated clusterization reconstruction for constructing long-lived, color-tunable, and processable phosphorescence cellulose

Developing color-tunable organic persistent room-temperature phosphorescence (p-RTP) materials are important in diverse optoelectronic applications but challenging. Here, stereospecific redox strategy is used to trigger clusterization reconstruction of cellulose in terms of clusterization structure and environment, resulting in long-lived and color-tunable phosphorescence of redox products. Extra unsaturated CO of oxidized 2,3-dialdehyde cellulose (DAC) and 2,3-dicarboxylic acid cellulose (DCC) can provide n-π* transition for enhanced spin–orbit coupling (SOC), facilitating the generation of triplet excitons. DAC with slow emission decay shows unique time-dependent afterglow; DCC would form different aggregated state, leading to a higher-energy blue afterglow. Reduced DAC (RDAC) provides more rigid crystalline environment for suppressing nonradiative relaxation, resulting in a striking lifetime of 799 ms. Finally, due to the long-lived, multicolor, and aqueous processable features, they are successfully applied in phosphorescence ink, screen printing, anti-counterfeit, and information encryption. The presented work fundamentally elucidates the role of clusterization reconstruction in p-RTP materials design.