Explore the worlds most powerful materials with nanographene research
Graphene, comprised of a single layer of carbon atoms in a honeycomb nanostructural arrangement, is the thinnest and strongest material yet known to science. Despite that this pristine carbon allotrope exhibits a variety of outstanding properties, its zero bandgap prevents its use for some optoelectronic applications. Fragments of graphene, or nanographenes, have shown a great potential to obviate these problems, thus paving the way for the development of chiroptical and optoelectronic properties.
Molecular Nanographenes constitutes a comprehensive overview on the synthesis of these materials and their properties. Covering their widely varying morphologies, their potential applications, and their valuable chiroptical and photophysical features, it also analyzes multiple approaches to obtain nanographene by using both top-down and bottom-up methodologies. The result is a one-stop shop for materials scientists and other researchers interested in these emergent and fascinating materials.
Molecular Nanographenes readers will also find:
A careful distinction between top-down and bottom-up approaches to nanographene synthesis Detailed discussion of nanographene configurations including planar, bilayer, helical, nanobelt, and many other geometries An authorial team with pioneering research experience in the study of nano-sized graphenes and their synthesis
Molecular Nanographenes is ideal for materials scientists, polymer chemists, solid state chemists, organic chemists, and any other researchers looking to work with shape and size-controlled flakes of graphenes.
Foreword xiii
Preface xvii
1 Aromaticity and Antiaromaticity in Nanographenes: An Overview 1
Albert Artigas and Miquel Solà
1.1 Introduction 1
1.2 Global and Local Aromaticity 2
1.3 Methods to Quantify Aromaticity 6
1.3.1 Energetic Descriptors of Aromaticity 7
1.3.2 Electronic Descriptors of Aromaticity 9
1.3.3 Geometric Descriptors of Aromaticity 13
1.3.4 Magnetic Descriptors of Aromaticity 14
1.4 The Analysis of Aromaticity in Nanographene Systems 20
1.5 Concluding Remarks 23
Acknowledgments 24
References 24
2 Covalent Patterned Functionalization of Graphene 31
Tao Wei and Andreas Hirsch
2.1 Introduction 31
2.2 Substrate-Mediated Chemical Patterning 33
2.3 Tip-Induced Patterned Functionalization 35
2.4 Lithography-assisted Molecular Engineering 37
2.5 Laser Writing 44
2.6 Conclusion 50
References 51
3 Nanographenes by Bottom-up Approach: The Scholl Reaction 55
Daniel T. Gryko, Wojciech D. Petrykowski, and Krzysztof J. Kochanowski
3.1 Introduction 55
3.2 Planar Nanographenes 56
3.3 Heterocyclic Analogs of Planar Nanographenes 63
3.4 Nonplanar, Curved, and Twisted Nanographenes 66
3.5 Heterocyclic Analogs of Nonplanar Nanographenes 71
3.6 Surface-assisted (cyclo)Dehydration 74
3.7 Summary and Outlook 76
Acknowledgment 77
References 77
4 Racemization Barriers in Chiral Molecular Nanographenes 83
Jesús M. Fernández-García, Patricia Izquierdo-García, Salvatore Filippone,
and Nazario Martín
4.1 Introduction 83
4.2 Structural Motifs for Chirality in Nanographenes 84
4.2.1 Gaussian Curvature 85
4.2.2 Helicenes 85
4.2.3 Rolling 86
4.2.4 Strain 87
4.3 Classification of Chiral Molecular NGs According to Their Isomerization
Barriers 87
4.4 Flexible Nanographenes (<5kcalmol 1) 87
4.5 Nanographenes with Spectroscopically Detectable Chirality (520 kcal mol
1) 89
4.6 Isolable Nanographenes (2035 kcal mol 1) 90
4.7 Rigid Nanographenes (>35 kcal mol 1) 93
4.8 Enantioselective Synthesis of Rigid Molecular Nanographenes 95
4.9 Conclusion 98
References 99
5 Synthesis of Helicenes 105
Irena G. Stará and Ivo Starý
5.1 Introduction 105
5.2 Characteristics of Helicenes 106
5.3 Synthetic Methodologies 107
5.3.1 Photocyclodehydrogenation of 1,2-Diaryl Olefins or Arenes 107
5.3.2 Oxidative Aromatic Coupling: Scholl Reaction 111
5.3.3 Transition Metal-Catalyzed [ 2 + 2 + 2] Cycloisomerization of
-Electron Systems 111
5.3.4 DielsAlder Cycloaddition of Aromatic Vinylethers with p-Benzoquinone
117
5.3.5 Transition Metal-Catalyzed Hydroarylation of Alkynes 119
5.3.6 Other Synthetic Approaches 120
5.4 Advanced Helicene Architectures 123
5.5 Summary and Outlook 137
Acknowledgment 137
References 137
6 Carbon Nanobelt History and Chemistry 149
Hiroki Shudo, Daiki Imoto, Akiko Yagi, and Kenichiro Itami
6.1 Introduction 149
6.2 Synthetic Attempts to CNBs 151
6.2.1 Some Synthetic Attempts to Cyclacenes 151
6.2.2 CNBs Observed by Mass Spectroscopy 152
6.2.3 Top-Down Approach to CNBs 152
6.3 Synthesis of CNBs 153
6.4 Synthesis of Related Aromatic Nanobelts 154
6.5 Synthesis of Topological Aromatic Nanobelts 157
6.6 Conclusion 159
References 159
7 Negatively Curved Nanographenes 163
Ka Man Cheung and Qian Miao
7.1 Introduction 163
7.2 Negatively Curved Nanographenes Containing Seven-Membered Rings 164
7.2.1 Incorporation of Seven-Membered Rings at an Early Stage of Synthesis
165
7.2.2 Formation of Seven-Membered Rings at a Late Stage of the Synthesis
168
7.3 Negatively Curved Nanographenes Containing Eight-Membered Rings 174
7.3.1 Incorporation of Eight-Membered Rings at an Early Synthetic Stage 175
7.3.2 Formation of Eight-Membered Rings at the Final Step of Synthesis 179
7.4 Structures and Stereochemical Dynamics and Properties 181
7.5 Negatively Curved Molecular Nanocarbons Beyond Nanographenes and
Bottom-up Approaches to Carbon Schwarzites 184
7.6 Conclusion and Outlook 186
References 188
8 From PAH-based Cyclophanes to Nanographenophanes 193
Parinaz Salari and Graham J. Bodwell
8.1 Introduction 193
8.2 Synthetic Considerations 197
8.3 Pentacenophanes (C22) 199
8.4 Indeno[ 2,3-b]triphenylenophanes (C25) 201
8.5 Dibenzo[ c,l]chrysenophanes (C26) 203
8.6 Dibenzo[ f,j]picenophanes (C30) and Tetrabenz[ a,c,h,j]anthracenes (c30)
205
8.7 Teropyrenophanes (C36) 207
8.8 A -Extended Azacorannulenophane (C36 N) 211
8.9 Hexabenzocoronenophanes (C42) 213
8.10 hept-Hexabenzocoronenophanes (C43) 217
8.11 Summary and Outlook 218
References 219
9 Bilayer and Multilayer Nanographenes: Synthesis and Properties 223
Patricia Izquierdo-García, Juan Lión-Villar, Jesús M. Fernández-García, and
Nazario Martín
9.1 Introduction 223
9.2 Van der Waals Molecular Nanographenes 225
9.3 Bilayers from Fused Radicals 230
9.4 Covalently Linked Bilayers 232
9.5 Conclusions 238
References 239
10 Large -Extended Carbon Nanorings: From Syntheses to Properties 243
Jinyi Wang, Dapeng Lu, and Pingwu Du
10.1 Introduction 243
10.1.1 Carbon Nanorings with Inserted Six-Membered Ring-Based PAHs 244
10.1.1.1 With Inserted Naphthalene(s) 244
10.1.1.2 With Inserted Anthracene(s) or Phenanthrene(s) 247
10.1.1.3 With Inserted Pyrene(s) or Perylene(s) 248
10.1.1.4 With Inserted Other PAHs 249
10.1.2 Carbon Nanorings Consisting Solely of PAHs 252
10.1.2.1 Consisting Solely of Naphthalenes 253
10.1.2.2 Consisting Solely of Anthracenes, Pyrenes, or Chrysenes 254
10.1.2.3 Consisting Solely of Other PAHs 255
10.1.3 CPP-based Oligomers and Polymers 258
10.1.4 Conclusions and Outlook 261
References 262
11 Nanographenes with Multiple Zigzag Edges 267
Ya Zou and Jishan Wu
11.1 Introduction 267
11.2 Peri-Acenes 268
11.3 Triangular Nanographenes 275
11.4 Peri-acenoacenes 278
11.5 Circumarenes 279
11.6 Conclusion 283
References 285
12 Synthesis of Graphene Nanoribbons, Nanographenes, and Fused Aromatic
Networks Through the Formation of Pyrazine Rings 289
Felix Hernández-Culebras and Aurelio Mateo-Alonso
12.1 Introduction 289
12.2 Graphene Nanoribbons and Nanographenes 289
12.3 Fused Aromatic Networks 293
12.4 Conclusions 300
References 300
13 Conjugated Nanohoops: Synthesis, Properties, and Applications 303
Birgit Esser, Philipp Seitz, Andrej Weber, and Jan S. Wössner
13.1 Introduction 303
13.2 Synthetic Strategies to Conjugated Nanohoops 303
13.2.1 Pt-, Ni-, or Au-Mediated Macrocyclizations in the Synthesis of
Nanohoops 304
13.2.2 Synthesis of Conjugated Nanohoops via Kinked Precursors to -System
Panels 307
13.3 Properties of Conjugated Nanohoops 309
13.3.1 Optoelectronic Properties 309
13.3.2 Chirality 311
13.3.3 HostGuest Chemistry 311
13.3.4 Solid-State Structures 313
13.4 Applications of Conjugated Nanohoops 314
13.4.1 Organic Electronics 314
13.4.2 Bottom-up Synthesis of Carbon Nanotubes 316
13.4.3 Biological Fluorophores 317
13.5 Conclusions 317
References 318
14 Chiral Polycyclic Aromatic Compounds with Monkey Saddle Topologies 323
Tobias Kirschbaum and Michael Mastalerz
14.1 Introduction 323
14.2 Saddle Mathematics 327
14.3 Synthesis 328
14.4 X-Ray Crystal Structures of Monkey Saddle PAHs 331
14.5 NICS and ACID Plots 333
14.6 Inversion Barriers and Chiroptical Properties 334
14.7 Other Monkey Saddle PAHs and Related Systems 337
14.8 Summary and Outlook 339
References 340
15 On-Surface Synthesis of -Conjugated Polymers 345
Nazario Martín and David Écija
15.1 Introduction 345
15.2 Content 345
15.3 Conclusions 358
References 360
16 Merging Organic Chemistry with Surface Science for the Preparation of
Nanographenes 363
Iago Pozo, Dolores Pérez, and Diego Peña
16.1 Introduction 363
16.2 Scanning Probe Microscopies for the Characterization of Nanographenes
Obtained by Solution-Phase Chemistry 364
16.3 Combining Solution-Phase and On-Surface Chemistry for the Synthesis of
Nanographenes 366
16.3.1 Surface-Assisted Cyclodehydrogenation Reaction 367
16.3.2 Surface-Assisted Ullmann-Type Reactions 369
16.3.3 Alternative Reactions Used for the On-Surface Preparation of
Nanographenes 371
16.3.4 Combining On-Surface Reactions Toward the Preparation of
Nanographenes 373
16.4 Concluding Remarks 373
References 375
17 Chiral Materials from Twistacenes and Helicenes 381
Si Tong Bao, Qifeng Jiang, Haoyu Jiang, Daniel avlovi, and Colin Nuckolls
17.1 Introduction 381
17.1.1 Background 381
17.1.2 The Building Block 381
17.2 Twistacene-based Materials 382
17.2.1 Preparation 382
17.2.2 Properties 383
17.2.3 Organic Photovoltaics and Photodetectors 388
17.2.4 Electrochemical Storage Using hPDIs 389
17.3 Helicene-Based Materials 391
17.3.1 Preparation 391
17.3.2 Chiral Amplification 392
17.4 Future Directions 393
References 393
18 Nanographene Diradicals 397
Fabrizia Negri and Juan Casado
18.1 Introduction 397
18.2 On the Origin of the Diradical State in Monocyclic Conjugated
Hydrocarbons: The Case of Cyclobutadiene 400
18.3 Nanographene Diradical Made from Mixtures of Quinoidal Bonding States
and Nonbonding States 403
18.3.1 The Zethrene Family 404
18.3.2 The Bisphenalenylene Family 406
18.3.3 On-Surface Diradicals 407
18.3.4 Graphene Nanoribbons and Their Diradical (i.e. Polyradical Character)
409
18.4 The Diradical State in All-Zig-zag Polycyclic Conjugated Hydrocarbons:
On the Reversed AromaticQuinoidal Way to Open-Shell Nanographenes 410
18.4.1 The Acenoacene Family 411
18.4.2 The Oligorylene Family 413
18.5 The Diradical State as a Result of Zig-zag Versus Arm-chair Structures
with Mobile Quinoidal Rings with Quinoidal Aromatic Transformation in the
Diradical State 415
18.5.1 The Peri-Acene Family 415
18.5.2 The Circumacene Family 417
18.5.3 The Unique Case of Rhombenes 419
18.6 Conclusions 420
Acknowledgments 420
References 420
19 Circularly Polarized Luminescence (CPL) in Nanographenes 425
Carlos M. Cruz, Sandra Míguez-Lago, Daniel Salvador-Gil, and Araceli G.
Campaña
19.1 Introduction 425
19.2 (1 × HBC)-Based Chiral Nanographenes 428
19.3 (1 × HBC)-Based Heteroatom-Doped Chiral Nanographenes 431
19.4 2 × HBC-Based Chiral Nanographenes 434
19.5 3 × HBC-based Chiral Nanographenes 436
19.6 4 × HBCs-based Chiral Nanographenes and Beyond 438
19.7 Summary Table and Outlook 439
Acknowledgments 445
References 445
20 Redox Properties of Nanographenes 449
Yikun Zhu and Marina A. Petrukhina
20.1 Introduction 449
20.2 Planar Nanographene Fragments 452
20.3 Contorted Nanographenes with Positive and Negative Curvatures 456
20.3.1 Corannulene-based Nanographenes 457
20.3.2 Cyclooctatetraene-based Nanographenes 463
20.3.3 Bilayer Nanographene 468
Acknowledgments 470
References 470
21 Kekulé and Non-Kekulé Nanographenes: A Magnetic Perspective 483
Fupeng Wu, Muhammad Imran, Ji Ma, and Xinliang Feng
21.1 Introduction 483
21.2 Stable Open-Shell Kekulé NGs (S = 0) as Quantum Units 485
21.3 Concealed Non-Kekulé Nanographenes (S = 0) 486
21.4 Obvious Non-Kekulé Nanographenes (S > 0) 488
21.4.1 Spin 1 / 2 Non-Kekulé Nanographenes (S = 1 / 2) 489
21.4.2 High-Spin Non-Kekulé Nanographenes (S 1) 492
21.5 Engineering of Magnetic Coupling in Non-Kekulé Nanographenes 498
21.5.1 Spin 1 / 2 Dimers 498
21.5.2 Triangulene (S = 1) Dimers and Trimers 501
21.5.3 [ 3]Triangulene (S = 1) Based Spin Chains 501
21.6 Summary and Outlook 504
Acknowledgments 505
References 505
Index 511
Nazario Martín, PhD, is Full Professor of Organic Chemistry at the University Complutense of Madrid and Vice-Director of the Institute of Madrid for Advanced Studies in Nanoscience, Madrid, Spain. He also served as editor-in-chief for the RSC Publications Journal of Materials Chemistry A, B and C. He has published extensively on carbon nanostructures and related subjects, and his many awards and honours include the 2012 Alexander von Humboldt award.
Colin P. Nuckolls, PhD, is Sheldon and Dorothea Professor of Materials Science at Columbia University, New York, USA, where he served as Department Chair from 2008-2011. He also serves as executive editor for the ACS Publications journal NanoLetters, and his wide research experience covers molecular synthesis, reaction chemistry, and many other subjects.
