Visible‐Light‐Driven Multifunctional Luminogens With More Than 150 Nm Absorption Band Separation for Dynamic Information Encryption

ABSTRACT Information security protection has become a fundamental issue in the human life, national security, and social stability, which is enabled through the use of multi‐responsive materials. Ideal multi‐responsive materials are operated with visible to near infrared light, exhibit large separation of absorption bands, and are functional by isomerization, posing an unmet challenge. Here, a series of visible‐light‐operated molecular photoswitches, ( E )‐1‐acetyl‐2‐((4‐(diphenylamino) phenyl) imino) indolin‐3‐one, and its derivatives ( PIO‐01/02/03/04/05 ), featuring near‐infrared second aggregation‐induced emission (AIE) and impressive acid/base‐driven switching, are constructed via twisted intramolecular charge transfer (TICT) and subsequent E / Z isomerization strategies. In addition, protonation not only endows these molecules with large separation (Δ λ max ) of over 100 nm, but also can be used as second independent input altering the light response. Based on calculation studies and advanced spectroscopic techniques, we provide the intricate interplay of the switching behavior of PIO‐01/02/03/04/05 on their photochemical properties. The optimized compound PIO‐01 shows significant applications in multi‐color, multi‐patterning display, transient information recording and erasing, and dual‐mode encryption‐decryption with ternary code.