Charge transfer materials fabricated by supramolecular strategy with a broad emission spectrum for realizing information encryption

Abstract

Novel charge transfer (CT) materials with a broad emission spectrum have been successfully developed in aqueous phase based on supramolecular self-assembly between different electron donors and electron acceptors. For electron donor BrAc (dimethylacridine-based derivative) with excellent self-aggregation property, it can co-aggregate with various electron acceptors to form nanoaggregates in water, leading to the multicolor CT emission with long luminescence lifetime. The emission colors cover from deep blue (425 nm) to orange (550 nm) region with lifetimes in the range of 61.2 ns–605.1 ns. As for the analogous donor (QaAc), which self-aggregation ability was poor, water-soluble pillar[5]arene (WP5) can be introduced to promote the aggregation to induce the similar CT emission. Moreover, reversible control of the CT emission and lifetime of BrAc-3TPYMB can be easily achieved via alternating addition of trifluoroacetic acid and triethylamine. Meanwhile, the donor–acceptor complex with white light emission can be conveniently constructed by incorporating three different acceptor molecules (3TMB, 3TPYMB, and TRZF2) with appropriate ratios. In addition, benefiting from the strong CT emission when donor and acceptor are close enough, thermal writing of quick response code and further information decryption has been successfully realized.