Handbook of Aggregation-Induced Emission, Volume 1

Youhong Tang is a Professor at Flinders University, Australia and actively works in aggregation-induced emission areas. Ben Zhong Tang is a Chair Professor at the Chinese University of Hong Kong, Shenzhen. He is widely known as the pioneer of the study of aggregation-induced emission.

• List of Contributors xvPreface to Handbook of Aggregation-Induced Emission xxiPreface to Volume 1: Fundamentals xxiii1 The Mechanistic Understanding of the Importance of Molecular Motions to Aggregation-induced Emission 1Junkai Liu and Ben Zhong Tang1.1 Introduction 11.2 Restriction of Intramolecular Motion 21.2.1 Restriction of Intramolecular Rotation 31.2.2 Restriction of Intramolecular Vibration 41.2.3 Ultrafast Insights into Tetraphenylethylene Derivatives 61.2.4 Theoretical Insights into Restriction of Intramolecular Motion 81.3 Restricted Access to Conical Intersection 121.4 Restriction of Access to the Dark State 141.5 Suppression of Kasha’s Rule 151.6 Through Space Conjugation 171.6.1 Clusterization-Triggered Emission 181.6.2 Polymerization-induced Emission 191.6.3 Excited-state Through-space Conjugation 191.7 Perspective 21References 232 Understanding the AIE Mechanism at the Molecular Level 27Xiaoyan Zheng and Qian Peng2.1 Introduction 272.2 Theoretical Methods 282.2.1 Radiative and Nonradiative Rate Constants 282.2.2 Computational Details 292.3 Revealed AIE Mechanism 312.3.1 Rotating Vibrations of Intramolecular Aromatic Ring 312.3.2 Stretching Vibrations of Bonds 332.3.3 Bending Vibration of Bonds 342.3.4 Flipping Vibrations of Molecular Skeletons 352.3.5 Twisting Vibration of Molecular Skeletons 362.4 Visualize Calculated Parameters in Experiments 372.4.1 Stokes Shift vs Reorganization Energy 372.4.2 Resonance Raman Spectroscopy (RSS) vs Reorganization Energy 382.4.3 Isotope Effect vs DRE 402.4.4 Linear Relationship between Fluorescence Intensity and Amorphous Aggregate Size 422.4.5 Pressure-induced Enhanced Emission (PIEE) 442.5 Molecular Design Based on AIE Mechanism 452.6 Summary and Outlook 46Acknowledgments 48References 483 Aggregation-induced Emission from the Restriction of Double Bond Rotation at the Excited State 55Ming Hu and Yan-Song Zheng3.1 Introduction 553.2 AIE Phenomena and Applications from RDBR Mechanism 583.2.1 Evolvement and Development of AIE Mechanisms 583.2.2 Investigation of RDBR AIE Mechanism by E/Z isomerization 643.2.3 Investigating of RDBR AIE Mechanism by Immobilization of TPE Propeller-like Conformation 693.2.4 Research of Theoretical Calculation on RDBR 783.2.5 Other AIEgens Involving RBDR Process 843.3 Conclusions 93References 944 The Expansion of AIE Thought: From Single Molecule to Molecular Uniting 99Qiuyan Liao, Qianqian Li, and Zhen Li4.1 Aggregation-Induced Emission 994.2 Photoluminescence Materials Based on Molecular Set 1014.3 Mechanoluminescence Materials Based on Molecular Set 1064.3.1 Mechanoluminescence Materials with Fluorescence Emission 1064.3.2 Mechanoluminescence Materials with Mechanical Induced Dual-or Tri-color Emission 1154.3.3 Quantitative Research of Mechanoluminescence Property 1214.4 Mechanochromism Materials 1224.4.1 Mechanochromism Materials Based on Polymorphs 1224.4.2 Mechanochromism Materials Based on Excimer Emission 1254.4.3 Other Kinds of Mechanochromism Materials 1284.5 Room Temperature Phosphorescence Materials Based on Molecular Uniting 1314.5.1 Room Temperature Phosphorescence Materials with Aromatics 1314.5.2 Room Temperature Phosphorescence Materials with Simple or Nonaromatic Structure 1404.5.3 Room Temperature Phosphorescence Materials with Multiple Emission 1424.5.4 Photoinduced Room Temperature Phosphorescence Materials 1444.6 Conclusion and Perspectives 147References 1475 Clusterization-Triggered Emission 153Haoke Zhang and Ben Zhong Tang5.1 Introduction 1535.2 Pure n-Electron Systems 1565.3 Pure π-Electron Systems 1605.4 (n, π)-Electrons Systems 1645.5 Other Systems 1665.6 Summary 167References 1686 Crystallization-induced Emission Enhancement 177Yong Qiang Dong, Yingying Liu, Mengyang Liu, Qian Wang, and Kang Wang6.1 Introduction 1776.2 Tetraphenylethylene Derivatives 1786.3 CIEE Active Luminogens with Bulky Conjugation Core 1836.3.1 Dibenzofulvene (DBF) Derivatives (Chart 6.2) 1836.3.2 9-([1,1′-Biphenyl]-4-ylphenylmethylene)-9H-xanthene 1856.3.3 Dicyanomethylenated Acridones 1866.3.4 Bis(diarylmethylene)dihydroanthracene [31] 1876.4 Other High-contrast CIEE Luminogens 1906.4.1 4-Dimethylamino-2-Benzylidene Malonic Acid Dimethyl Ester 1906.4.2 Diphenyl Maleimide Derivatives [33] 1916.4.3 3,4-Bisthienylmaleic Anhydride [34] 1926.4.4 Boron-containing CIEE Luminogens 1936.5 Potential Applications 1966.5.1 Volatile Organic Compounds (VOCs) Sensor 1966.5.2 OLED 1966.5.3 High-density Data Storage 1976.5.4 Mechanochromic (MC) Luminescent Sensor 1986.6 Summary and Perspective 198References 1987 Surface-fixation Induced Emission 203Yohei Ishida and Shinsuke Takagi7.1 Introduction 2037.2 What Happened to the Characteristics of Molecules on the Clay Mineral Nanosheets 2057.3 Clay–Molecular Complexes 2067.4 Absorption Spectra of Clay–Molecular Complexes 2077.5 Emission Enhancement Phenomenon in Clay–Molecular Complexes: S-FIE 2087.6 Mechanism of Surface-Fixation Induced Emission 2117.7 Summary and Outlook 214Acknowledgment 215References 2158 Aggregation-induced Delayed Fluorescence 221Yan Fu, Hao Chen, Zujin Zhao, and Ben Zhong Tang8.1 Introduction 2218.2 Novel Aggregation-induced Delayed Fluorescence Luminogens 2228.3 Conclusion and Outlook 247References 2479 Homogeneous Systems to Induce Emission of AIEgens 251Kenta Kokado and Kazuki Sada9.1 Introduction 2519.2 Homogeneous Solution 2529.2.1 Complexation with Anions 2539.2.2 Complexation with Cations 2549.2.3 Inclusion Complexes 2569.2.4 Adhesion on Macromolecules 2579.2.5 Steric Hindrance 2589.2.6 Covalent Linkage 2599.3 Liquid 2609.4 Gels and Network Polymers 2619.4.1 Chemically Crosslinked Gels 2619.4.2 Physically Crosslinked Gels 2629.5 Crystalline Materials 2649.6 Outlook and Future Perspectives 266References 26610 Hetero-aggregation-induced Tunable Emission (HAITE) Through Cocrystal Strategy 273Yinjuan Huang and Qichun Zhang10.1 Introduction 27310.2 Interactions Within Organic Cocrystals 27410.3 Preparation of Organic Cocrystals 27510.4 Molecular Stacking Modes Within Organic Cocrystals 27610.5 Characterization of Organic Cocrystals 27710.6 HAITE Through Cocrystal Strategy 27710.6.1 HAITE with Tunable Color and Enhanced Emission 27810.6.1.1 Insignificant Changed Intensity but Tuned Color 27810.6.1.2 Enhanced Emission and Tuned Color 28710.6.2 HAITE with Increased PLQY but Intrinsic Color 29110.6.3 HAITE: Thermally Activated Delayed Fluorescence 29710.6.4 HAITE-phosphorescence 30010.7 Summary and Outlook 302References 30411 Anti-Kasha Emission from Organic Aggregates 311Wenbin Huang and Zikai He11.1 Introduction 31111.2 Anti-Kasha Emission from Aromatic Carbonyl Compounds in Aggregates 31211.3 Anti-Kasha Emission from Azulene Compounds in Aggregate 32211.4 Anti-Kasha Emission from Other Unconventional Aromatic Compounds in Aggregates 32411.5 Conclusions 327References 32712 Aggregation-enhanced Emission: From Flexible to Rigid Cores 333Harnimarta Deol, Gurpreet Singh, Vandana Bhalla, and Manoj Kumar12.1 Introduction 33312.2 Freely Moving Rotors-induced Emission Enhancement 33412.3 Guest-induced Emission Enhancement 34412.4 Conclusion 366Acknowledgment 367References 36713 Room-temperature Phosphorescence of Pure Organics 371Tianwen Zhu, Zihao Zhao, Tianjia Yang, and Wang Zhang Yuan13.1 Introduction 37113.2 Fundamental Mechanism in Organic Phosphorescence 37213.2.1 Photophysical Process for Phosphorescence 37213.2.2 Theoretical Study on Phosphorescent Process 37313.3 Recent Progress in Organic RTP Materials 37513.3.1 Crystallization-induced RTP 37513.3.1.1 Heavy Atom Effect 37613.3.1.2 Molecular Interaction 38013.3.1.3 H-aggregation 38013.3.2 Doping in Rigid Matrix-induced RTP 38213.3.2.1 Host–Guest System 38513.3.2.2 Doping in Polymer Matrix 38713.3.3 Clustering-triggered RTP 38913.3.3.1 Natural Products 38913.3.3.2 Synthetic Compounds 39413.3.4 Other Systems 39913.3.4.1 Amorphous Organics 39913.3.4.2 Organic Framework 39913.3.4.3 Supramolecular Organics 40213.3.4.4 Hybrid Perovskites 40313.3.5 Applications 40513.4 Conclusions and Perspectives 405References 40714 A Global Potential Energy Surface Approach to the Photophysics of AIEgens: The Role of Conical Intersections 411Rachel Crespo-Otero and Lluís Blancafort14.1 Introduction 41114.2 Methodological Aspects 41214.2.1 Intramolecular Restriction Models and the FGR-based Approach 41214.2.2 A PES-based Description of Photochemical Mechanisms 41214.2.3 Computational Approaches for Excited States 41614.2.3.1 Electronic Structure Methods for Excited States 41614.2.3.2 Dynamics Simulations in the Context of AIE 42014.2.4 Methods for Large Systems 42014.3 CI-centered Global PES for AIEgens 42414.3.1 Double-bond Torsion 42414.3.2 Double-bond Torsion vs Cyclization in TPE Derivatives 42814.3.3 Excited-state Intramolecular Proton Transfer (ESIPT) Compounds 43114.3.4 Ring Puckering 43214.3.5 Bond Stretching 43514.3.6 A View of AIE Based on the RACI Model and the Global PES 43614.4 Crystallization-induced Phosphorescence 43614.5 Effect of Intermolecular and Intramolecular Interactions on the Photophysics of AIEgens 43714.5.1 Excitonic Effects in AIE 43714.5.2 Effect of Intramolecular and Intermolecular Interactions on Emission Color 43914.6 New Challenges 43914.6.1 The Role of Dark States in AIE 43914.6.2 Pressure-induced Emission Enhancement 44014.6.3 AIE in Transition Metal (TM) Compounds 44214.7 Conclusions and Outlook 443References 44415 Multicomponent Reactions as Synthetic Design Tools of AIE and Emission Solvatochromic Quinoxalines 455Lukas Biesen and Thomas J. J. Müller15.1 Introduction 45515.2 Synthetic Approaches to Quinoxalines via Multicomponent Reactions and One-Pot Processes 45615.3 Photophysical Properties and Emission Solvatochromicity of Quinoxalines 46215.4 AIE Characteristics and Effects of Quinoxalines 46815.5 Conclusion 476Acknowledgments 476References 47616 Aggregation-induced Emission Luminogens with Both High-luminescence Efficiency and Charge Mobility 485Ying Yu, Zheng Zhao, and Ben Zhong Tang16.1 Introduction 48516.2 p-Type OSCs 48716.3 n-Type OSCs 49516.4 Ambipolar OSCs 50016.5 Conclusion and Perspective 505References 50517 Morphology Modulation of Aggregation-induced Emission: From Thermodynamic Self-assembly to Kinetic Controlling 509Kaizhi Gu, Chenxu Yan, Zhiqian Guo, and Wei-Hong Zhu17.1 Introduction 50917.2 Aggregation Modulation of AIE Bioprobes via Hydrophilicity Improvement 51117.2.1 Molecular Modification 51117.2.2 Polymerization with Hydrophilic Matrix 51517.3 Thermodynamic Self-assembly of AIE Materials 51917.4 Morphology Tuning of AIE Nanoaggregates 51917.5 Kinetic-driven Preparation of AIE NPs 52317.6 Conclusion and Outlook 527References 52718 AIE-active Polymer 531Rong Hu, Anjun Qin, and Ben Zhong Tang18.1 Introduction 53118.2 Photophysical Properties 53218.2.1 Quantum Yield 53218.2.2 Photosensitization 53618.2.3 Two-photon Absorption and Emission 53818.2.4 Circularly Polarized Luminescence 54018.3 Applications 54118.3.1 Chem-sensor 54118.3.2 Bioimaging 54318.3.3 Therapy Applications 54618.4 Conclusion and Perspective 549Acknowledgments 550References 55019 Liquid-crystalline AIEgens: Materials and Applications 555Kyohei Hisano, Supattra Panthai, and Osamu Tsutsumi19.1 Introduction 55519.2 Materials: Molecular Design 55619.2.1 Discotic LC AIEgen 55619.2.2 Calamitic LC AIEgens 56119.2.3 Polymeric LC AIEgens 56619.3 Applications of LC AIEgens 56719.3.1 Linearly Polarized Luminescence 56719.3.2 Circularly Polarized Luminescence 56819.4 Conclusion 571References 57120 Push–Pull AIEgens 575Andrea Nitti and Dario Pasini20.1 Introduction 57520.2 Basic Concept of Molecular Design 57620.2.1 Photophysical Excited States in Aggregates 57620.2.2 Fundamental Molecular Design to Achieve Push–Pull AIEgens 57920.3 Push–Pull AIEgens from Rotor Structure 58120.3.1 Double Bond Stator 58220.3.2 Point-restricted Rotors from Atoms or Functional Groups 58420.3.3 Aromatic Rotors 58720.4 Push–Pull AIEgens from ACQ Chromophores 58920.4.1 BT-based AIEgens 58920.4.2 Cyanine and DCM-based AIEgens 59420.4.3 QM-based AIEgens 59520.4.4 DPP-based AIEgens 59720.4.5 Rylene-based AIEgens 59920.5 Concluding Remarks 602References 602Index 609