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 (Δλ_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.

Keywords

acid response / aggregation-induced emission / information ciphering / molecular logic gate / molecular motor / photoresponse

References

[1] A. N. Kolmogorov, “On Certain Asymptotic Characteristics of Completely Bounded Metric Spaces,” Doklady Akademii nauk SSSR 108 (1956): 385-388.

[2] G. Allwein, in Proceedings of the 2004 Workshop on New Security Paradigms-NSPW ’04 (ACM Press, 2005): 23-31.

[3] F. Fabris, “Shannon Information Theory and Molecular Biology,” Journal of Interdisciplinary Mathematics 12 (2009): 41-87.

[4] S. Z. Pu, Q. Sun, C. B. Fan, R. J. Wang, and G. Liu, “Recent Advances in Diarylethene-Based Multi-responsive Molecular Switches,” Journal of Materials Chemistry 4 (2016): 3075-3093.

[5] Y. Fan, X. Jin, M. Wang, et al., “Multimode Dynamic Photoluminescent Anticounterfeiting and Encryption Based on a Dynamic Photoluminescent Material,” Journal of Chemical Engineering 393 (2020): 124799.

[6] R. Xu, M. Feng, J. Xie, et al., “Physically Unclonable Holographic Encryption and Anticounterfeiting Based on the Light Propagation of Complex Medium and Fluorescent Labels,” ACS Applied Materials and Interfaces 16 (2024): 2888-2901.

[7] W. Qu, Z. Bi, C. Zou, and C. Chen, “Light, Heat, and Force-Responsive Polyolefins,” Advanced Science 11 (2024): 2307568.

[8] D. H. Qu, Q. C. Wang, Q. W. Zhang, X. Ma, and H. Tian, “Photoresponsive Host-Guest Functional Systems,” Chemical Reviews 115 (2015): 7543-7588.

[9] D. Veselý, J. Jančík, M. Weiter, et al., “Fast E/Z UV-Light Response T-type Photoswitching of Phenylene-Thienyl Imines,” Journal of Photochemistry and Photobiology A 430 (2022): 113994.

[10] Z. Wang, L. Li, W. Wang, et al., “Self-Assembled Nanoparticles Based on Cationic Mono-/AIE Tetra-Nuclear Ir(iii) Complexes: Long Wavelength Absorption/Near-Infrared Emission Photosensitizers for Photodynamic Therapy,” Dalton Transactions 52 (2023): 1595-1601.

[11] D. Dahal, P. Ray, and D. Pan, “Unlocking the Power of Optical Imaging in the Second Biological Window: Structuring Near-Infrared II Materials From Organic Molecules to Nanoparticles,” Wires Nanomedicine and Nanobiotechnology 13 (2021): e1734.

[12] Y. Shan, Q. Zhang, J. Sheng, M. C. A. Stuart, D. Qu, and B. L. Feringa, “Motorized Photomodulator: Making a Non-Photoresponsive Supramolecular Gel Switchable by Light,” Angewandte Chemie International Edition 62 (2023): e202310582.

[13] H. Chen, W. Chen, Y. Lin, Y. Xie, S. H. Liu, and J. Yin, “Visible and Near-Infrared Light Activated Azo Dyes,” Chinese Chemical Letters 32 (2021): 2359-2368.

[14] S. Jia and E. M. Sletten, “Spatiotemporal Control of Biology: Synthetic Photochemistry Toolbox With Far-Red and Near-Infrared Light,” ACS Chemical Biology 17 (2022): 3255-3269.

[15] S. Samanta, A. A. Beharry, O. Sadovski, et al., “Photoswitching Azo Compounds in Vivo With Red Light,” Journal of the American Chemical Society 135 (2013): 9777-9784.

[16] A. D. W. Kennedy, I. Sandler, J. Andréasson, J. Ho, and J. E. Beves, “Visible-Light Photoswitching by Azobenzazoles,” Chemistry - A European Journal 26 (2020): 1103-1110.

[17] J. N. Bull, M. S. Scholz, N. J. A. Coughlan, and E. J. Bieske, “Isomerisation of an Intramolecular Hydrogen-Bonded Photoswitch: Protonated Azobis(2-imidazole),” Physical Chemistry Chemical Physics 19 (2017): 12776-12783.

[18] Y. Liao, “Design and Applications of Metastable-State Photoacids,” Accounts of Chemical Research 50 (2017): 1956-1964.

[19] Y. Qin, N. Niu, X. Li, et al., “Long-Term In Vivo Fluorescence Analyses and Imaging-Guided Tumor Surgery in the Second Near-Infrared Window Using a Supramolecular Metallacage,” Aggregate 6 (2025): e708.

[20] Y. Zhou, S. Zhang, W. Zhang, et al., “Donor-Acceptor Conjugated Copolymers Containing Difluorothienylethylene-Bridged Methyleneoxindole or Methyleneazaoxindole Acceptor Units: Synthesis, Properties, and Their Application in Field-Effect Transistors,” Macromolecules 51 (2018): 7093-7103.

[21] M. Medved, M. W. H. Hoorens, M. Di Donato, et al., “Tailoring the Optical and Dynamic Properties of Iminothioindoxyl Photoswitches Through Acidochromism,” Chemical Science 12 (2021): 4588-4598.

[22] S. C. Cheng, K. J. Chen, Y. Suzaki, et al., “Reversible Laser-Induced Bending of Pseudorotaxane Crystals,” Journal of the American Chemical Society 140 (2018): 90-93.

[23] C. Chen and C. Fang, “Devising Efficient Red-Shifting Strategies for Bioimaging: A Generalizable Donor-Acceptor Fluorophore Prototype,” Chemistry - An Asian Journal 15 (2020): 1514-1523.

[24] Y. Huang, B. Gao, Q. Huang, D. Ma, H. Wu, and C. Qian, “Constructing Benzothiadiazole-based Donor‒acceptor Corganic Frameworks for Efficient Photocatalytic H2 Evolution,” Aggregate 6 (2025): e669.

[25] S. Crespi, N. A. Simeth, M. Di Donato, et al., “Phenylimino Indolinone: A Green-Light-Responsive T-Type Photoswitch Exhibiting Negative Photochromism,” Angewandte Chemie International Edition 60 (2021): 25290-25295.

[26] C. Wang, W. Chi, Q. Qiao, D. Tan, Z. Xu, and X. Liu, “Twisted Intramolecular Charge Transfer (TICT) and Twists Beyond TICT: From Mechanisms to Rational Designs of Bright and Sensitive Fluorophores,” Chemical Society Reviews 50 (2021): 12656-12678.

[27] T. Fischer, J. Leitner, A. Gerwien, et al., “Mechanistic Elucidation of the Hula-Twist Photoreaction in Hemithioindigo,” Journal of the American Chemical Society 145 (2023): 14811-14822.

[28] M. Sun, X. Zhao, X. Cao, et al., “Acceptor-Donor-Acceptor Type Organic Photothermal Agents With Enhanced NIR Absorption and Photothermal Conversion Effect for Cancer Photothermal Therapy,” Talanta 274 (2024): 125991.

[29] P. Chaudhary, S. Gupta, N. Muniyappan, S. Sabiah, and J. Kandasamy, “An Efficient Synthesis of N-Nitrosamines Under Solvent, Metal and Acid Free Conditions Using Tert-Butyl Nitrite,” Green Chemistry 18 (2016): 2323-2330.

[30] H. Sun, Y. Wu, Y. Xiao, J. Zhao, Z. Xie, and T. Yu, “Promoting Intense Mechanoluminescence by Strengthening C-H⋯π Interactions in Thioxanthene Derivatives,” Dyes and Pigments 211 (2023): 111054.

[31] M. W. H. Hoorens, M. Medved″, A. D. Laurent, et al., “Iminothioindoxyl as a Molecular Photoswitch With 100 Nm Band Separation in the Visible Range,” Nature Communications 10 (2019): 2390.

[32] C. Petermayer and H. Dube, “Indigoid Photoswitches: Visible Light Responsive Molecular Tools,” Accounts of Chemical Research 51 (2018): 1153-1163.

[33] J. Ni, X. Zhang, G. Yang, et al., “A Photoinduced Nonadiabatic Decay-Guided Molecular Motor Triggers Effective Photothermal Conversion for Cancer Therapy,” Angewandte Chemie International Edition 59 (2020): 11298-11302.

[34] M. Medved’, M. Di Donato, W. J. Buma, et al., “Mechanistic Basis for Red Light Switching of AzoniumIons,” Journal of the American Chemical Society 145 (2023): 19894-19902.

[35] C. Feid, L. Luma, T. Fischer, et al., “Iminothioindoxyl Donors With Exceptionally High Cross Section for Protein Vibrational Energy Transfer,” Angewandte Chemie International Edition 63 (2024): e202317047.

[36] Z. Han, M. He, G. Wang, J. Lehn, and Q. Li, “Visible-Light-Driven Solid-State Fluorescent Photoswitches for High-Level Information Encryption,” Angewandte Chemie International Edition 63 (2024): e202416363.

[37] X. Luo, J. Li, C. Li, et al., “Reversible Switching of the Emission of Diphenyldibenzofulvenes by Thermal and Mechanical Stimuli,” Advanced Materials 23 (2011): 3261-3265.

[38] Z. Chen, Z. Li, L. Yang, et al., “Novel Diisocyano-Based Dinuclear Gold(I) Complexes With Aggregation-Induced Emission and Mechanochromism Characteristics,” Dyes and Pigments 121 (2015): 170-177.

[39] Y. Ren, A. Kravberg, S. Xie, et al., “Stimuli-responsive enaminitrile molecular switches as tunable AIEgens covering the chromaticity space, operating out-of-equilibrium, and acting as vapor sensors,” Aggregate 6 (2025): e659.

[40] G. He, W. Torres Delgado, D. J. Schatz, et al., “Coaxing Solid-State Phosphorescence From Tellurophenes,” Angewandte Chemie International Edition 53 (2014): 4587-4591.

[41] C. Petermayer, S. Thumser, F. Kink, P. Mayer, and H. Dube, “Hemiindigo: Highly Bistable Photoswitching at the Biooptical Window,” Journal of the American Chemical Society 139 (2017): 15060-15067.

[42] H. Xie, J. Wang, Z. Lou, et al., “Mechanochemical Fabrication of Full-Color Luminescent Materials From Aggregation-Induced Emission Prefluorophores for Information Storage and Encryption,” Journal of the American Chemical Society 146 (2024): 18350-18359.

[43] X. Cui, H. Li, H. Lu, et al., “Highly Efficient Solution-processed Organic Photovoltaics Enabled by Improving Packing Behavior of Organic Semiconductors,” Science China Chemistry 67 (2024): 890-897.

[44] Y. Gui, Y. Wang, D. Wang, et al., “Thiophene π-Bridge Manipulation of NIR-II AIEgens for Multimodal Tumor Phototheranostics,” Angewandte Chemie International Edition 63 (2024): e202318609.

[45] R. Li, K. Liu, Q. Hu, et al., “NIR-II AIEgens Nanosystem for Fluorescence and Chemiluminescence Synergistic Imaging-Guided Precise Resectionin Osteosarcoma Surgery,” Aggregate 6 (2025): e658.

[46] S. Scheiner and T. Kar, “Substituent Effects Upon Protonation-Induced Red Shift of Phenyl−Pyridine Copolymers,” Journal of Physical Chemistry B 106 (2002): 534-539.

[47] S. Zhen, Z. Xu, M. Suo, et al., “NIR-II AIE Liposomes for Boosting Type-I Photodynamic and Mild-Temperature Photothermal Therapy in Breast Cancer Treatment,” Advanced Materials 37 (2025): 2411133.

[48] J. Wudka, “Remarks on the Born-Oppenheimer Approximation,” Physical Review D 41 (1990): 712-714.

[49] Y. Fu, H. Liu, B. Z. Tang, and Z. Zhao, “Realizing Efficient Blue and Deep-Blue Delayed Fluorescence Materials With Record-Beating Electroluminescence Efficiencies of 43.4%,” Nature Communications 14 (2023): 2019.

[50] T. Lu and Q. Chen, “Shermo: A General Code for Calculating Molecular Thermochemistry Properties,” Computational & Theoretical Chemistry 1200 (2021): 113249.

[51] L. Liu, P. Liu, L. Ga, and J. Ai, “Advances in Applications of Molecular Logic Gates,” ACS Omega 6 (2021): 30189-30204.

[52] C. Zhang, L. Shen, C. Liang, Y. Dong, J. Yang, and J. Xu, “DNA Sequential Logic Gate Using Two-Ring DNA,” ACS Applied Materials and Interfaces 8 (2016): 9370-9376.

[53] M. Gao, R. Wu, Y. Zhang, et al., “New Molecular Photoswitch Based on the Conformational Transition of Phenothiazine Derivatives and Corresponding Triplet Emission Properties,” Journal of the American Chemical Society 147 (2025): 2653-2663.

[54] J. Bai, Z. Shi, and X. Jiang, ““Acrostic” Encryption: Stress-Manipulation on Information Display,” Advanced Functional Materials 33 (2023): 2301797.

[55] M. He, C. Ding, Z. Han, et al., “Visible-Light-Driven [2+2] Photocycloaddition in Self-Assembled State for Time-Resolved Information Encryption,” Advanced Optical Materials (2025): 2403525.

[56] M. He, C. Ding, H. Guo, and Q. Li, “Room Temperature Phosphorescence Materials Based on Small Organic Molecules: Design Strategies and Applications,” Responsive Materials 2 (2024): e20240014.

[57] P. Zhang, G. Wang, and H. Yu, “Ultraviolet-Visible-Near-Infrared Light-Responsive Soft Materials: Fabrication, Photomechanical Deformation and Applications,” Responsive Materials 2 (2024): e20240016.

[58] S. Cai, W. Deng, F. Huang, et al., “Light-Driven Reversible Intermolecular Proton Transfer at Single-Molecule Junctions,” Angewandte Chemie International Edition 58 (2019): 3829-3833.

[59] Z. Qi, Y. J. Ma, and D. Yan, “One-Dimensional Molecular Co-Crystal Alloys Capable of Full-Color Emission for Low-Loss Optical Waveguide and Optical Logic Gate,” Aggregate 5 (2024): e411.

[60] Y. Zhang, Y. Wang, Y. Dai, et al., “Chirality Logic Gates,” Science Advances 8 (2022): eabq8246.

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2025 The Author(s). Aggregate published by SCUT, AIEI and John Wiley & Sons Australia, Ltd.