Preface .................................................. XIII
List of Contributors ..................................... XVII
List of Abbreviations ..................................... XXI
1. An Introduction to Chirality at the Nanoscale ............... 1
Laurence D. Barron
1.1. Historical Introduction to Optical Activity
and Chirality ......................................... 1
1.2. Chirality and Life .................................... 4
1.2.1. Homochirality ................................. 4
1.2.2. Pasteur's Conjecture .......................... 7
1.3. Symmetry and Chirality ................................ 8
1.3.1. Spatial Symmetry .............................. 8
1.3.2. Inversion Symmetry: Parity, Time Reversal
and Charge Conjugation ........................ 9
1.3.3. True and False Chirality ..................... 10
1.3.4. Symmetry Violation ........................... 14
1.3.5. Symmetry Violation versus Symmetry
Breaking ..................................... 16
1.3.6. Chirality in Two Dimensions .................. 17
1.4. Absolute Enantioselection ............................ 18
1.4.1. Truly Chiral Influences ...................... 18
1.4.2. Falsely Chiral Influences .................... 20
1.5. Spectroscopic Probes of Chirality in Nanosystems ..... 21
1.5.1. Electronic Optical Activity .................. 22
1.5.2. Vibrational Optical Activity ................. 23
1.6. Conclusion ........................................... 24
References ................................................. 24
2. Optically Active Supramolecules ............................ 29
Alessandro Scarso and Giuseppe Borsato
2.1. Introduction to Supramolecular Stereochemistry ....... 29
2.1.1. Survey of Weak Intermolecular Attractive
Forces ....................................... 31
2.1.2. Timescale of Supramolecular Interactions
and Racemization Processes ................... 33
2.2. Self-Assembly of Intrinsically Chiral Molecular
Capsules ............................................. 37
2.2.1. Hydrogen-Bonded Assemblies ................... 37
2.2.1.1. Double Rosettes .................... 37
2.2.1.2. Hydrogen-Bonded Capsules ........... 39
2.2.2. Metal-ligand Assemblies ...................... 43
2.3. Chiral Induction in the Formation of Supramolecular
Systems .............................................. 46
2.3.1. Chiral Memory Effect in Hydrogen-Bonded
Assemblies ................................... 46
2.3.2. Chiral Memory Effect in Metal-Ligand
Assemblies ................................... 49
2.4. Chiral Spaces for Chiral Recognition ................. 51
2.4.1. Enantioselective Recognition within Chiral
Racemic Self-Assembled Hosts ................. 52
2.4.1.1. Hydrogen-Bonded Hosts .............. 52
2.4.1.2. Metal-Ligand Hosts ................. 53
2.4.2. Interguests Chiral Sensing within Achiral
Self-Assembled Hosts ......................... 56
2.4.2.1. Hydrogen-Bonded Hosts .............. 57
2.4.2.2. Metal-Ligand Hosts ................. 60
2.5. Conclusion and Outlook ............................... 61
References ................................................. 62
3. Chiral Nanoparticles ....................................... 67
Cyrille Gautier and Thomas Bürgi
3.1. Introduction ......................................... 67
3.2. Nanoparticle Properties and Synthesis ................ 68
3.2.1. Nanoparticle Properties ...................... 68
3.2.2. Preparation, Purification and Size
Separation ................................... 71
3.2.2.1. Preparation ........................ 71
3.2.3. Purification and Separation of
Nanoparticles ................................ 74
3.3. Chiroptical Properties of Inorganic Nanoparticles .... 74
3.3.1. Vibrational Circular Dichroism ............... 74
3.3.2. Circular Dichroism ........................... 75
3.3.3. Origin of Optical Activity in Metal-Based
Transitions .................................. 78
3.4. Optically Active Coordination Clusters ............... 80
3.5. Nanoparticles of Chiral Organic Compounds ............ 82
3.6. Applications ......................................... 83
3.6.1. Asymmetric Catalysis ......................... 83
3.6.2. Nanoparticles in Liquid-Crystal Media ........ 85
3.6.3. Chiral Discrimination ........................ 87
3.7. Outlook .............................................. 87
References ................................................. 87
4. Gels as a Media for Functional Chiral Nanofibers ........... 93
Sudip Malik, Norifumi Fujita, and Seiji Shinkai
4.1. A Brief Introduction to Gels ......................... 93
4.1.1. Introduction ................................. 93
4.1.2. Definition of Gels ........................... 94
4.1.3. Classification of Gels ....................... 94
4.1.4. Chirality in Gels ............................ 95
4.2. Chiral Organogels .................................... 96
4.2.1. Steroid-Based Chiral Gelators ................ 96
4.2.2. Pyrene-Based Chiral Gelators ................ 103
4.2.3. Diaminoyclohexane-Based Chiral Gelators ..... 103
4.2.4. OPV-Based Chiral Gelators ................... 105
4.3. Chiral Hydrogels .................................... 108
4.3.1. Chiral Fatty Acids .......................... 108
4.3.2. Chiral Sugar-Based Gelators ................. 109
4.3.3. Miscellaneous Chiral Hydrogelators .......... 110
4.3.3.1. The Future of Chiral Gels in
Nanoscience and Nanotechnology .... 111
References ................................................ 111
5. Expression of Chirality in Polymers ....................... 115
Teresa Sierra
5.1. Historical Perspective on Chiral Polymers ........... 115
5.2. Chiral Architecture Control in Polymer Synthesis .... 117
5.2.1. Polymerization of Chiral Assemblies ......... 117
5.2.1.1. Chiral Organization Through
H-Bonding Interactions ............ 118
5.2.1.2. Chiral Organization Through
π-Stacking Interactions ........... 120
5.2.1.3. Chiral Organization Through
Mesogenic Driving Forces .......... 121
5.2.2. Control of Chiral Architecture During
Polymerization .............................. 123
5.2.2.1. Polymerization in Chiral
Solvents .......................... 123
5.2.2.2. Polymerization with Chiral
Templates ......................... 127
5.2.2.3. Polymerization of Chiral
Assemblies by Circularly
Polarized Radiation ............... 128
5.2.3. Chiral Architecture Control upon
Polymerization: Noncovalent Interactions .... 129
5.2.3.1. Control of the Chiral
Architecture by H-Bonding
Interactions ...................... 129
5.2.3.2. Control of the Chiral
Architecture by π-Stacking and
Steric Factors .................... 133
5.2.3.3. Chiral Superstructures by π-
Interactions: Chiral Aggregates ... 134
5.3. Asymmetry Induction in Nonchiral Polymers ........... 137
5.3.1. Induction Through Noncovalent Interaction
with Chiral Molecules ....................... 137
5.3.1.1. Chiral Induction by Acid-Base
Interactions ...................... 137
5.3.1.2. Chiral Induction by Host-Cation
Interactions ...................... 143
5.3.1.3. Chiral Induction by Metal
Coordination ...................... 143
5.3.2. Induction Through Noncovalent Interaction
with Chiral Polymers ........................ 146
5.3.3. Induction Through the Formation of
Inclusion Complexes ......................... 147
5.3.4. Induction by a Chiral External Stimulus ..... 150
5.3.4.1. Solvent-Induced Chirality ......... 150
5.3.4.2. Light-Induced Chirality ........... 151
5.4. Chiral Memory Effects. Tuning Helicity .............. 154
5.4.1. Memory Effects from Chiral Polymers ......... 154
5.4.1.1. Temperature- and/or Solvent-
Driven Memory Effects ............. 154
5.4.1.2. Light-Driven Memory Effects ....... 157
5.4.2. Memory Effects from Achiral Polymers ........ 158
5.5. Chiral Block-Copolymers and Nanoscale Segregation ... 161
5.5.1. Chiral Block-Copolymers: Nanoscale
Segregation in the Bulk ..................... 162
5.5.2. Chiral Block-Copolymers: Nanoscale
Segregation in the Mesophase ................ 162
5.5.3. Chiral Block-Copolymers: Nanoscale
Segregation in Solvents. Amphiphilic
Block-Copolymers ............................ 165
5.6. Templates for Chiral Objects ........................ 169
5.6.1. Templates for Chiral Supramolecular
Aggregates .................................. 169
5.6.1.1. Templating with Natural Helical
Polymers .......................... 169
5.6.1.2. Templating with Synthetic
Helical Polymers .................. 172
5.6.2. Molecular Imprinting with Helical
Polymers .................................... 174
5.6.3. Templating by Wrapping with Helical
Polymers .................................... 175
5.6.4. Alignment of Functional Groups .............. 176
5.6.4.1. Polyisocyanides ................... 176
5.6.4.2. Polypeptides ...................... 178
5.6.4.3. Polyacetylenes .................... 178
5.6.4.4. Foldamers ......................... 179
5.7. Outlook ............................................. 180
References ................................................ 181
6. Nanoscale Exploration of Molecular and Supramolecular
Chirality at Metal Surfaces under Ultrahigh-Vacuum
Conditions ................................................ 191
Rasmita Raval
6.1. Introduction ........................................ 191
6.2. The Creation of Surface Chirality in 1D
Superstructures ..................................... 192
6.3. The Creation of 2D Surface Chirality ................ 196
6.3.1. 2D Supramolecular Chiral Clusters at
Surfaces .................................... 196
6.3.2. 2D Covalent Chiral Clusters at Surfaces ..... 199
6.3.3. Large Macroscopic 2-D Chiral Arrays ......... 200
6.3.4. Chiral Nanocavity Arrays .................... 204
6.4. Chiral Recognition Mapped at the Single-Molecule
Level ............................................... 205
6.4.1. Homochiral Self-Recognition ................. 205
6.4.2. Diastereomeric Chiral Recognition ........... 207
6.4.2.1. Diastereomeric Chiral
Recognition by Homochiral
Structures ........................ 207
6.4.2.2. Diastereomeric Chiral
Recognition by Heterochiral
Structures ........................ 209
6.5. Summary ............................................. 211
References ................................................ 212
7. Expression of Chirality in Physisorbed Monolayers
Observed by Scanning Tunneling Microscopy ................. 225
Steven De Feyter, Patrizia Iavicoli, and Hong Xu
7.1. Introduction ........................................ 215
7.2. How to Recognize Chirality at the Liquid/Solid
Interface ........................................... 217
7.2.1. Chirality at the Level of the Monolayer
Symmetry .................................... 217
7.2.2. Chirality at the Level of the Monolayer -
Substrate Orientation ....................... 219
7.2.3. Determination Absolute Configuration ........ 220
7.3. Chirality in Monolayers Composed of Enantiopure
Molecules ........................................... 221
7.4. Polymorphism ........................................ 228
7.5. Is Chirality Always Expressed? ...................... 230
7.6. Racemic Mixtures: Spontaneous Resolution? ........... 231
7.6.1. Chiral Molecules ............................ 231
7.6.2. Achiral Molecules ........................... 234
7.7. Multicomponent Structures ........................... 237
7.8. Physical Fields ..................................... 240
7.9. Outlook ............................................. 240
References ................................................ 243
8. Structure and Function of Chiral Architectures of
Amphiphilic Molecules at the Air/Water Interface .......... 247
Isabelle Weissbuch, Leslie Leiseroivitz,
and Meir Lahav
8.1. An introduction to Chiral Monolayers on Water
Surface ............................................. 247
8.2. Two-Dimensional Crystalline Self-Assembly of
Enantiopure and Racemates of Amphiphiles at the
Air/Water Interface; Spontaneous Segregation of
Racemates into Enantiomorphous 2D Domains ........... 248
8.3. Langmuir Monolayers of Amphiphilic α-Amino Acids .... 249
8.3.1. Domain Morphology and Energy Calculations
in Monolayers of N-acyl-α-Amino Acids ....... 253
8.4. Stochastic Asymmetric Transformations in Two
Dimensions at the Water Surface ..................... 254
8.5. Self-Assembly of Diastereoisomeric Films at the
Air/Water Interface ................................. 255
8.6. Interactions of the Polar Head Groups with the
Molecules of the Aqueous Environment ................ 256
8.7. Interdigitated Bi- or Multilayer Films on the
Water Surface ....................................... 261
8.8. Structural Transfer from 2D Monolayers to 3D
Crystals ............................................ 263
8.9. Homochiral Peptides from Racemic Amphiphilic
Monomers at the Air/Water Interface ................. 265
8.10. Conclusions ......................................... 268
References ................................................ 268
9. Nanoscale Stereochemistry in Liquid Crystals .............. 271
Carsten Tschierske
9.1. The Liquid-Crystalline State ........................ 272
9.2. Chirality in Liquid Crystals Based on Fixed
Molecular Chirality ................................. 273
9.2.1. Chiral Nematic Phases and Blue Phases ....... 274
9.2.2. Chirality in Smectic Phases ................. 276
9.2.3. Polar Order and Switching in Chiral LC
Phases ...................................... 276
9.2.3.1. Ferroelectric and
Antiferroelectric Switching ....... 276
9.2.3.2. Electroclinic Effect .............. 279
9.2.3.3. Electric-Field-Driven
Deracemization .................... 279
9.2.4. Chirality Transfer via Guest-Host
Interactions ................................ 279
9.2.5. Induction of Phase Chirality by External
Chiral Stimuli .............................. 281
9.2.6. Chirality in Columnar LC Phases ............. 282
9.3. Chirality Due to Molecular Self-Assembly of
Achiral Molecules ................................... 284
9.3.1. Helix Formation in Columnar Phases .......... 284
9.3.2. Helical Filaments in Lamellar Mesophases .... 287
9.4. Polar Order and Chirality in LC Phases Formed by
Achiral Bent-Core Molecules ......................... 288
9.4.1. Phase Structures and Polar Order ............ 288
9.4.2. Superstructural Chirality and
Diastereomerism ............................. 290
9.4.3. Switching of Superstructural Chirality ...... 291
9.4.4. Macroscopic Chirality and Spontaneous
Reflection Symmetry Breaking in
"Banana Phases" ............................. 292
9.4.4.1. Layer Chirality ................... 292
9.4.4.2. Dark Conglomerate Phases .......... 292
9.5. Spontaneous Reflection-Symmetry Breaking in Other
LC Phases ........................................... 295
9.5.1. Chirality in Nematic Phases of Achiral
Bent-Core Molecules ......................... 295
9.5.2. Spontaneous Resolution of Racemates in LC
Phases of Rod-Like Mesogens ................. 295
9.5.3. Deracemization of Fluxional Conformers via
Diastereomeric Interactions ................. 296
9.5.4. Chirality in Nematic, Smectic and Cubic
Phases of Achiral Rod-Like Molecules ........ 296
9.5.5. Segregation of Chiral Conformers in Fluids,
Fact or Fiction? ............................ 296
9.6. Liquid Crystals as Chiral Templates ................. 298
9.7. Perspective ......................................... 299
References ................................................ 299
10. The Nanoscale Aspects of Chirality in Crystal Growth:
Structure and Heterogeneous Equilibria .................... 305
Gérard Coquerel and David B. Amabilino
10.1. An introduction to Crystal Symmetry and Growth
for Chiral Systems. Messages for Nanoscience ........ 305
10.2. Supramolecular Interactions in Crystals ............. 308
10.2.1. Hydrogen Bonds .............................. 309
10.2.2. Interaromatic Interactions .................. 310
10.2.3. Electrostatic Interactions .................. 311
10.2.4. Modulation of Noncovalent Interactions
with Solvent ................................ 312
10.2.5. Polymorphism ................................ 312
10.3. Symmetry Breaking in Crystal Formation .............. 312
10.3.1. Spontaneous Resolution of Chiral
Compounds ................................... 313
10.3.2. Spontaneous Resolution of Achiral
Compounds ................................... 315
10.4. Resolutions of Organic Compounds .................... 317
10.5. Resolutions of Coordination Compounds with Chiral
Counterions ......................................... 320
10.6. Thermodynamic Considerations in the Formation of
Chiral Crystals ..................................... 322
10.6.1. What is the Order of a System Composed of
Two Enantiomers? ............................ 322
10.6.2. Resolution by Diastereomeric Associations ... 331
10.7. Influencing the Crystallization of Enantiomers ...... 335
10.7.1. Solvent ..................................... 335
10.7.2. Preferential Nucleation and Inhibition ...... 336
10.8. Chiral Host-Guest Complexes ......................... 338
10.9. Perspectives ........................................ 341
References ................................................ 341
11. Switching at the Nanoscale: Chiroptical Molecular
Switches and Motors ....................................... 349
Wesley R. Browne, Dirk Pijper, Michael M. Pollard,
and Ben L. Feringa
11.1. Introduction ........................................ 349
11.2. Switching of Molecular State ........................ 351
11.3. Azobenzene-Based Chiroptical Photoswitching ......... 354
11.4. Diarylethene-Based Chiroptical Switches ............. 359
11.5. Electrochiroptical Switching ........................ 364
11.6. Molecular Switching with Circularly Polarized
Light ............................................... 366
11.7. Diastereomeric Photochromic Switches ................ 368
11.8. Chiroptical Switching of Luminescence ............... 370
11.9. Switching of Supramolecular Organization and
Assemblies .......................................... 372
11.10.Molecular Motors .................................... 373
11.11.Chiral Molecular Machines ........................... 374
11.12.Making Nanoscale Machines Work ...................... 380
11.13.Challenges and Prospects ............................ 386
References ................................................ 387
12. Chiral Nanoporous Materials ............................... 391
Wenbin Lin and Suk Joong Lee
12.1. Classes of Chiral Nanoporous Materials .............. 391
12.2. Porous Chiral Metal-Organic Frameworks .............. 392
12.3. Porous Oxide Materials .............................. 397
12.4. Chiral Immobilization of Porous Silica Materials .... 400
12.5. Outlook ............................................. 406
References ................................................ 407
Index ......................................................... 411
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