Handbook of Aggregation-Induced Emission, Volume 2

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 xvii

Preface to Handbook of Aggregation-Induced Emission xxiii

Preface to Volume 2: Typical AIEgens Design xxv

1 Tetraphenylpyrazine-based AIEgens: Synthesis and Applications 1
Ming Chen, Anjun Qin, and Ben Zhong Tang

1.1 Introduction 1

1.2 Synthesis of TPP-based AIEgens 3

1.2.1 Cyclization Reaction 3

1.2.2 Suzuki–Miyaura Reaction 7

1.3 Functionalities of TPP-based AIEgens 8

1.3.1 Organic Light-emitting Diodes 8

1.3.2 Fluorescent Sensors 9

1.3.3 Chiral Cage for Self-assembly to Achieve White-light Emission 13

1.3.4 Metal–organic Framework 15

1.4 Conclusion 17

References 18

2 AIEgens Based on 9,10-Distyrylanthracene (DSA): From Small Molecules to Macromolecules 23
Leijing Liu, Bin Xu, and Wenjing Tian

2.1 Introduction 23

2.2 Application of AIE Luminogens Based on 9,10-Distyrylanthracene 24

2.2.1 Smart Materials with Stimulus Response 24

2.2.1.1 Piezofluorochromic Materials 24

2.2.1.2 Photochromic Materials 27

2.2.1.3 Thermochromic Materials 27

2.2.1.4 Acidichromic Materials 27

2.2.1.5 Multistimuli-responsive Materials 30

2.2.2 High Solid-state Luminescent Materials 30

2.2.3 Fluorescent Materials for Bioimaging 35

2.2.4 Fluorescent Probes for Chemical and Biological Sensing 41

2.2.4.1 Fluorescent Probes for Chemical Sensing 41

2.2.4.2 Fluorescent Probes for Biological Sensing 44

2.3 Conclusions and Outlook 46

Acknowledgments 47

References 47

3 Typical AIEgens Design: Salicylaldehyde Schiff Base 53
Yue Zheng and Aijun Tong

3.1 Introduction 53

3.1.1 AIE and ESIPT of Salicylaldehyde Schiff Base 53

3.1.2 Universal Design of SSB-based AIEgens 55

3.2 Fluorescent Probes 55

3.2.1 Metal Ion Detection and Imaging 55

3.2.2 Biologically and Environmentally Related Molecular Detection and Imaging 63

3.2.3 Ratiometric pH Probes 76

3.2.4 Bioimaging 76

3.3 Fluorescent Materials 81

3.3.1 Solid Fluorescence Emitting and Stimuli-Responsive Materials 81

3.3.2 Nanoparticles 88

3.4 Summary and Perspectives 91

References 92

4 Diaminodicyanoquinodimethanes: Fluorescence Emission Enhancement  in Aggregates and Solids 97
N. Senthilnathan and T. P. Radhakrishnan

4.1 Introduction 97

4.1.1 Molecular Materials 97

4.1.2 ‘Push–Pull’ Molecules 97

4.1.3 Diaminodicyanoquinodimethanes 98

4.2 Nonlinear Optical Materials based on DADQs 100

4.2.1 Molecular Hyperpolarizability 100

4.2.2 SHG Materials 100

4.2.3 Structure–Property Correlations 101

4.3 Enhanced Fluorescence in Aggregates and Solids Based on DADQs 102

4.3.1 Remote Functionalized Systems 102

4.3.2 Color Tuning, Nanocrystals, and Colloids 103

4.3.3 Ultrathin Films 105

4.3.4 New Directions 105

4.4 Mechanistic Insights into the Enhanced Fluorescence 106

4.4.1 Relevance of Intramolecular Effects 106

4.4.2 Role of Intermolecular Effects 106

4.5 Impact of Crystallinity on the Fluorescence Response 108

4.5.1 Amorphous-to-Crystalline Transformation: Fluorescence Switching and Tuning 108

4.5.2 Reversible Amorphous–Crystalline Transformations: Phase Change Materials 108

4.5.3 Impact of External Stimuli 110

4.6 Emergent and Potential Applications of DADQs 110

4.6.1 Electroluminescence and Nonlinear Optics 110

4.6.2 Bioimaging 110

4.6.3 Photoelectrochemical and Photobioelectrochemical Applications 112

4.6.4 Memory Devices 112

4.7 Concluding

Remarks 113

Acknowledgements 114

References 114

5 Aggregation-induced Emission from the Sixth Main Group 119
Jan Balszuweit, Bibhisan Roy, and Jens Voskuhl

5.1 Introduction 119

5.2 Oxygen 119

5.2.1 Oxygen-Containing Heterocycles 120

5.2.2 Oxo-ether Containing AIE-Active Luminogens 122

5.3 Sulfur 126

5.3.1 Luminogens Based on Thiophenes 126

5.3.2 Thioethers with Aggregation-Induced Emission Properties 129

5.3.3 Emissive Sulfones 131

5.4 Selenium and Tellurium 132

5.4.1 Selenium-Containing Luminophores 132

5.4.2 Tellurium-Containing Luminophores 134

5.5 Conclusion 138

Acknowledgment 138

References 138

6 Fluorescence Detection of Dynamic Aggregation Processes Using AIEgens: Hexaphenylsilole and Cyanostilbene 143
Fuyuki Ito

6.1 Introduction 143

6.2 Selective Detection of Phase Transformation During Evaporative Crystallization of Hexaphenylsilole 145

6.3 Observation of the Initial Stage of Organic Crystal Formation During Solvent Evaporation Using a Cyanostilbene Derivative 149

6.4 Chemometrix Analysis of the Aggregated Structure of Cyanostilbene in a Reprecipitation Solution Using Fluorescence Excitation Spectroscopy 152

6.5 UV-triggered Fluorescence Enhancement of a Dicyanostilbene Derivative Film Cast from an Ethanol Solution 158

6.6 Concluding Remarks 162

Acknowledgments 162

References 162

7 Cyclic Triimidazole Derivatives: An Intriguing Family of Multifaceted Emitters 165
Elena Cariati, Elena Lucenti, Andrea Previtali, and Alessandra Forni

7.1 Introduction 165

7.2 The Protoype: Cyclic Triimidazole 166

7.3 Halogenated Derivatives of Cyclic Triimidazole 175

7.3.1 Bromine Derivatives 176

7.3.2 Iodine Derivatives 179

7.4 Organic Derivatives 184

7.4.1 2-Fluoropyridine Derivative 185

7.4.2 Tribenzoimidazole Derivative 186

7.5 Hybrid Inorganic/Organic Derivatives 188

7.6 Conclusions 191

Acknowledgments 191

References 191

8 Synthesis of Multi-phenyl-substituted Pyrrole (MPP)-based AIE Materials and Their Applications 195
Zhengxu Cai, Yunxiang Lei, and Yuping Dong

8.1 Introduction 195

8.2 Modular Approach: Systematic Synthesis of MPPs 196

8.3 Structures and Photophysical Properties 198

8.4 Applications of MPP-based Materials 204

8.4.1 Chemical/Biological Sensing 204

8.4.2 Multi-stimulus Response Materials 208

8.4.3 Optoelectronic Systems 210

8.4.4 Biological Application 213

8.5 Conclusion and Outlook 216

References 216

9 Development of a New Class of AIEgens: Tetraarylpyrrolo [3,2-b] Pyrroles (TAPPs) 221
Vishal G. More, Ratan W. Jadhav, Mohammad Al Kobaisi, Lathe A. Jones, and Sheshanath V. Bhosale

9.1 Introduction 221

9.2 The Accidental Discovery of TAPP 223

9.3 Synthesis of TAPP 223

9.4 Possible Mechanism of TAPP Synthesis 227

9.5 Reactivity of TAPP 228

9.6 π-Expansion of TAPP 229

9.7 π-Expanded 1,4-dihydropyrrolo[3,2-b] pyrrole 231

9.8 Photophysical Optical Properties of TAPP 239

9.9 Conclusion and Outlook 245

Acknowledgments 247

References 247

10 Small Molecule Organogels from AIE Active α-Cyanostilbenes 255
Jagadish Katla, Beena Kumari, and Sriram Kanvah

10.1 Introduction 255

10.2 Organogels with Trifluoromethyl Substitution 256

10.3 Organogels with Chiral Units/Chiral Hosts 260

10.4 Stimuli–Responsive Organogels 262

10.5 Organogels with Sensing Applications 266

10.6 Concluding Remarks 271

Acknowledgments 271

References 271

11 Stimuli-responsive Pure Organic Luminescent Supramolecules 277
Siyu Sun and Xiang Ma

11.1 Introduction 277

11.2 Pure Organic Fluorescent Supramolecules 280

11.2.1 Pure Organic Fluorescent Supramolecules Containing Macrocycles 280

11.2.1.1 Pure Organic Fluorescent Supramolecules Containing Cyclodextrins 280

11.2.1.2 Pure Organic Fluorescent Supramolecules Containing Calixarenes 284

11.2.1.3 Pure Organic Fluorescent Supramolecules Containing Cucurbiturils 284

11.2.1.4 Pure Organic Fluorescent Supramolecules Containing Pillararene 288

11.2.1.5 Pure Organic Fluorescent Supramolecules Containing Crown Ether 290

11.2.2 Pure Organic Fluorescent Supramolecules Without Macrocycles 291

11.3 Pure Organic Phosphorescent Supramolecules 293

11.3.1 Pure Organic Phosphorescent Supramolecules Based on Macrocyclic Molecules 293

11.3.1.1 Pure Organic Phosphorescent Supramolecules Containing Cyclodextrin 293

11.3.1.2 Pure Organic Phosphorescent Supramolecules Containing Cucurbiturils 297

11.3.1.3 Pure Organic Phosphorescent Supramolecules Containing Calixarenes 297

11.3.1.4 Pure Organic Phosphorescent Supramolecules Containing Crown Ether 297

11.3.2 Pure Organic Phosphorescent Supramolecules Without Macrocyclic Molecules 299

11.3.2.1 Pure Organic Supramolecular Phosphorescence System With Doping-Based Host–Guest Interaction 299

11.3.2.2 Other Pure Organic Phosphorescent Supramolecules 301

11.4 Conclusions 306

Acknowledgments 306

References 307

12 AIE Fluorescent Polymersomes 311
Hui Chen and Min-Hui Li

12.1 Introduction 311

12.2 Structural Consideration of Block Copolymers for Polymersome Formation 314

12.3 Methods of Polymersome Preparation 315

12.4 Techniques of Polymersome Characterization 317

12.5 AIE Polymersomes Based on PEG-b-POSS 317

12.6 AIE Polymersomes Based on Amphiphilic Polypeptoids 319

12.7 AIE Polymersomes Based on PEG-b-Polycarbonate 321

12.8 AIE Polymersomes Based on Amphiphilic Polynorbornene 323

12.9 AIE Polymersomes Based on Amphiphilic Block Copolymers by RAFT Polymerization 326

12.10 Summary and Perspectives 330

References 334

13 Designs for AIE Molecules and Functional Luminescent Materials Based on Boron-containing Element-blocks 341
Kazuo Tanaka, Masayuki Gon, Shunichiro Ito, and Yoshiki Chujo

13.1 Introduction 341

13.1.1 Generals of Commodity Luminescent Boron Complexes 341

13.1.2 Trends in the Development of Advanced Organic Electronic Devices 342

13.1.3 Strategies for Obtaining Solid-state Luminescence and Stimuli-responsiveness 343

13.1.4 New Ideas for Material Design Based on “Element-blocks” 343

13.2 Solid-state Luminescence and Luminochromism of o-Carboranes 344

13.2.1 Emission Mechanism of Aryl-modified o-Carboranes 344

13.2.2 AIE Behavior of o-Carborane Materials 344

13.2.3 Formation of Twisted Intramolecular Charge Transfer (TICT) State in the Crystalline State of o-Carboranes 346

13.2.4 Thermochromic Luminescence of o-Carboranes 346

13.2.5 Intense Solid-state Luminescent Molecules 347

13.2.6 Solid-state Excimer Emission 348

13.3 Boron Complexes with β-Ketimine and β-Diketimine Ligands 349

13.3.1 Generals of Boron Ketiminates and Diketiminates 349

13.3.2 Unique Solid-state Luminescent Properties of Conjugated Boron Complexes 350

13.3.3 Thermally Stable Mechanochromic Luminescent Hybrid with the Siloxane Unit 350

13.3.4 Luminescent Properties of β-Diketiminate Complexes 352

13.3.5 AIE-active Conjugated Polymers 352

13.3.6 Design for Film-type Sensors 353

13.3.7 Sensitive Luminochromic Sensors with Gallium Complexes 354

13.4 Rational Design for AIE-active Molecules Based on “Flexible” Boron Complexes 355

13.4.1 Concept for Rational Design 355

13.4.2 Ring-fused or Nonring-fused Molecules 355

13.4.3 Thermosalient-active Molecules 357

13.4.4 Solid-state Luminescent π-Conjugated Polymer 358

13.5 Conclusion 359

References 359

14 Aggregation-induced Emission (AIE) Active Metal–Organic Coordination Complexes 367
Xueliang Shi, Xuzhou Yan, and Hai-Bo Yang

14.1 Introduction 367

14.2 Conception and Design Strategy 368

14.3 AIE Active Metallacycles 371

14.3.1 AIE Active Simple Metallacycles 371

14.3.2 AIE Active Fused Metallacycles 378

14.3.3 AIE Active Metallacycle Polymers 382

14.4 AIE Active Metallacages 389

14.5 AIE Active Metal–organic Frameworks (MOFs) 397

14.6 Summary and Outlook 405

Acknowledgments 406

References 406

15 AIE-type Luminescent Metal Nanoclusters 411
Zhennan Wu, Qiaofeng Yao, and Jianping Xie

15.1 Introduction 411

15.2 In the “Single-cluster” Scenario 412

15.2.1 AIE-type Luminescent Metal NCs 412

15.2.2 Atomically Precise AIE-type Luminescent Metal NCs 416

15.2.3 Approaches to Luminescence Enhancement of Metal NCs in the Scheme of AIE 418

15.2.3.1 Surface Engineering 418

15.2.3.2 Roles of the Core 422

15.3 Beyond the “Single-cluster” Scenario 423

15.3.1 Poor-solvent-induced AIE of Metal NCs 423

15.3.2 Ion-induced AIE of Metal NCs 423

15.3.3 Supramolecular Interactions Induced AIE of Metal NCs 426

15.3.4 Spatial Confinement-induced AIE of Metal NCs 429

15.4 Application of the AIE-type Luminescent Metal NCs 433

15.4.1 Chemical Sensing 433

15.4.2 Biological Applications 434

15.4.3 Photosensitizer 434

15.4.4 Light-emitting Diodes (LEDs) 434

15.5 Conclusion and Outlook 436

References 437

16 Aggregation-induced Emission in Coinage Metal Clusters 443
Shuang-Quan Zang and Kai Li

16.1 Introduction 443

16.2 AIE-active Gold Cluster 444

16.3 AIE-active Silver Cluster 450

16.4 AIE-active Copper Cluster 454

16.5 AIE-active Bimetallic Cluster 462

16.6 Conclusions 465

References 466

17 Activated Alkynes in Metal-free Bioconjugation 471
Xianglong Hu and Ben Zhong Tang

17.1 Introduction 471

17.2 Alkyne–Azide-based Bioconjugation 472

17.3 Activated Alkyne–Amine-based Bioconjugation 473

17.4 Activated Alkyne–Thiol-based Bioconjugation 480

17.5 Activated Alkyne–Hydroxyl-based Bioconjugation 483

17.6 Activated Alkyne-based Bioconjugation and Polymerization in Living Cells and Pathogens 484

17.7 Conclusion 488

References 488

18 AIE-active BODIPY Derivatives 493
Yali Liu, Yuzhang Huang, Rongrong Hu, and Ben Zhong Tang

18.1 Introduction 493

18.2 Structures of BODIPY Derivatives 495

18.2.1 BODIPY Derivatives Without Other Chromophore 495

18.2.2 TPE-containing BODIPYs 496

18.2.3 TPA-containing BODIPYs 498

18.2.4 Benzodithiophene-containing BODIPYs 499

18.2.5 Chiral BODIPYs 500

18.2.6 Metal-containing BODIPYs 502

18.2.7 BODIPY-containing Polymers 503

18.2.8 Other BODIPY Derivatives 504

18.3 Structural–property Relationship 508

18.3.1 Conjugation Effect 508

18.3.2 Number and Position of Substitutes 508

18.3.3 Substitution Group 513

18.3.4 Alkyl Substitutes on BODIPY Core 516

18.3.5 AIEgens Attached Through Nonconjugated Spacers 518

18.3.6 Other Substitution Structures 519

18.4 Application 522

18.4.1 Chemosensor 522

18.4.2 Bioimaging 526

18.5 Conclusion 532

References 532

19 Photochemistry-regulated AIEgens and Their Applications 537
Xia Ling and Meng Gao

19.1 Introduction 537

19.2 Photocleavage Reaction 537

19.3 Photoreduction Reaction 539

19.4 Photocyclodehydrogenation Reaction 540

19.5 Photooxidative Dehydrogenation Reaction 543

19.6 Spiropyran-merocyanine Reversible Conversion 544

19.7 Dithienylethene-based Ring-open/-closing Reaction 545

19.8 Enol–Keto Isomerization Reaction 550

19.9 E/Z Isomerization Reaction 552

19.10 Photo-induced [2 + 2] Cycloaddition 554

19.11 Combinational Photoreactions 554

19.12 Conclusion and Outlook 556

References 556

20 Design and Development of Naphthalimide Luminogens 559
Niranjan Meher and Parameswar Krishnan Iyer

20.1 Introduction 559

20.2 Naphthalimides with N-Functionalization (I) 564

20.3 Naphthalimides Substituted at the 4th Position with Oxygen Atom (II) 567

20.4 Naphthalimides Substituted at the 4th Position with Nitrogen Atom (III) 570

20.5 Naphthalimides with C−C Aromatic Substitution (IV) 571

20.6 Naphthalimides with C−C Double-and Triple-Bond Substitutions (V and VI) 574

20.7 Naphthalimides with the Significant Role of Multifunctionalization (VII) 576

20.8 Conclusion and Outlooks 580

References 581

Index 587