A Dihydroazulene‐Based Photofluorochromic AIE System for Rewritable 4D Information Encryption

Abstract

Dynamic patterns based on luminescent materials play an essential role in the digital age. However, it is still challenging to develop highly emissive photofluorochromic materials with dynamic behaviors to store information with multiple characteristics. Here, we report a series of dihydroazulene‐based compounds which show typical aggregation‐induced emission (AIE) effect. Moreover, the photo‐switching ability of the dihydroazulene units, undergoing light‐induced ring‐opening, enables photofluorochromic properties. The photofluorochromism also shows quantitively described responses to time and temperature via a reverse ring‐closing process. Ultimately, a rewritable 4D information system, embedded with a quick response code, dot matrix with microstructures, color matrix of fluorescence, and time/temperature‐dependent intensity change, is established with dynamic patterns. This work not only develops a dynamic AIE skeleton with photofluorochromic properties but also provides a new strategy for information encryption and cybernetics.

Achieving Color‐Tunable and Time‐Dependent Organic Long Persistent Luminescence via Phosphorescence Energy Transfer for Advanced Anti‐Counterfeiting

“…To prevent counterfeiting that has become an ever-growing serious threat to governments, companies, and customers, various anti-counterfeiting techniques including watermarks, laser holography, bar codes, 2D codes, and luminescence printing have been developed, among which luminescence printing shows significant advantages of tunable luminescence, simple operation, high-throughput, and facile design. [1][2][3][4][5][6][7][8][9] Therefore, fluorescent inks and labels have been widely used in identity cards, currencies, and tags.…”

Hydrazone‐Based AIEgens with Photofluorochromic Ability for Rewritable, Intensity‐Variable, and High‐Resolution Photopattern

“…The ONIOM method with a combined quantum mechanics and molecular mechanics (QM/MM) approach was applied to simulate the electronic structures and properties of TPAHPy in the gaseous and aggregate states (Figure S20, Supporting Information). [ 12 ] As shown in Figure 1f,g, the total reorganization energy (λ) of the crystalline state (λ = 2917 cm −1 ) was found to be lower than that of the total gaseous state (λ = 3916 cm −1 ), indicating the rigid excited‐state structure which blocked the most of the nonradiative‐decay channel in the aggregate/crystalline phase. Further, the dihedral angle (θ) in the aggregate state (θ = 16.78%) was also reduced when compared to the gaseous state (θ = 38.78%), suggesting the minimal rotation or restriction of intramolecular motion (RIM) in the aggregate state.…”

A Multiresponsive Functional AIEgen for Spatiotemporal Pattern Control and All‐round Information Encryption

“…Dynamic coloration, on the other hand, is particularly interesting for applications like information encryption and 4D printing [8, 12b] . Because of the reversible amination process of CPVCM, a written quick response (QR) code was further manufactured through photopatterning on an initial AIE plate.…”