Table of Contents
Preface vii
List of Important Abbreviations and Symbols xiii
List of Numbered Chemical Structures xv
Chapter 1 Introduction 1
1.1 Supramolecular chemistry 2
1.2 Host-guest inclusion complexation in solution 5
References 11
Chapter 2 Historical aspects 15
2.1 Early examples of host-guest inclusion compounds 17
2.2 History of the development of major families of hosts 18
2.3 Proliferation of host-guest inclusion research 23
2.4 Current state of solution-phase host-guest inclusion chemistry 25
References 26
Chapter 3 Driving forces, thermodynamics, and kinetics of inclusion in aqueous solution 31
3.1 Preparation, self-assembly, and mechanisms of inclusion complexation in aqueous solution 32
3.2 Driving forces for inclusion in aqueous solution 40
3.2.1 Intermolecular forces between host and guest 41
3.2.2 Expulsion of water molecules from the host cavity 44
3.2.3 The hydrophobic effect in aqueous solution 45
3.2.4 Summary of driving forces for host inclusion in aqueous solution 47
3.3 Thermodynamics of inclusion in solution 47
3.4 Dynamics of inclusion in solution 51
3.5 Host selectivity and modes of inclusion in solution 53
References 55
Chapter 4 Spectroscopic methods for studying host-guest inclusion in solution 61
4.1 Quantum mechanics and molecular energy levels 63
4.2 The nature of light and its interaction with molecules 67
4.3 Infrared absorption spectroscopy 70
4.4 UV-vis absorption spectroscopy 72
4.5 Fluorescence spectroscopy 77
4.5.1 Steady-state fluorescence spectroscopy 87
4.5.2 Time-resolved fluorescence spectroscopy 94
4.6 Phosphorescence spectroscopy 99
4.7 NMR spectroscopy 100
4.8 Other spectroscopic methods and conclusion 105
References 107
Chapter 5 Other experimental methods for studying host-guest inclusion in solution 113
5.1 Electrochemical methods 113
5.2 Calorimetric and other thermal methods 116
5.3 Chromatographic methods 119
5.4 Mass spectrometry methods 123
5.5 Diffraction techniques 125
5.6 Other miscellaneous methods 130
References 130
Chapter 6 Extraction of binding constants from experimental data 135
6.1 Extraction of binding constants from experimental titration data for 1:1 host:guest complexes 136
6.1.1 Benesi-Hildebrand Analysis 137
6.1.1.1 Modifications of the Benesi-Hildebrand method for applications to other types of experimental data 138
6.1.1.2 Accuracy and limitations of the Benesi-Hildebrand method 139
6.1.2 Nonlinear least-squares analysis of fluorescence titration data 140
6.2 Experimental determination of host:guest complex stoichiometry 143
6.3 Extraction of binding constants from experimental data for higher order host:guest complexes 144
6.4 Error analysis and reproducibility of binding constants extracted from experimental titration data 146
6.5 Other mathematical and/or experimental approaches 147
References 148
Chapter 7 Cyclodextrins as hosts 151
7.1 Introduction to cyclodextrins 151
7.2 Physicochemical properties of cyclodextrins 153
7.3 Modified cyclodextrins 156
7.3.1 Substitution at the primary hydroxyls 158
7.3.2 Substitution at the secondary hydroxyls 158
7.3.3 Specific examples of modified cyclodextrins used as molecular hosts 159
7.3.4 Monosubstitution of tethered active moieties 161
7.4 Host properties of native and modified CDs in aqueous solution 163
7.5 Polymers containing CD host moieties 171
7.6 Summary of CDs as molecular hosts 173
References 173
Chapter 8 Cucurbit[n]urils as hosts 177
8.1 Introduction to cucurbit[n]urils 177
8.2 Synthesis of cucurbit[n]urils 178
8.3 Physicochemical properties of cucurbit[n]urils 182
8.4 Cucurbit[n]urils as molecular hosts in aqueous solution 184
8.4.1 Cucurbituril (Cucurbit[6]uril) as host 187
8.4.2 Cucurbit[7]urit as host 192
8.4.3 Cucurbit[n]urils, n ≥ 8 as hosts 196
8.5 A Comparison of the aqueous host binding properties of cucurbit[n]urils and CDs 198
8.6 Cucurbit[n]uril derivatives and analogues as hosts in aqueous solution 200
8.7 Cucurbit[n]urils as molecular beads in rotaxanes and building blocks for nanodevices 203
8.8 Summary of cucurbit[n]urils as molecular hosts 204
References 205
Chapter 9 Other molecular hosts in aqueous solution 209
9.1 Calix[n]arenes 209
9.2 Cavitands 213
9.3 Cryptands 215
9.4 Cryptophanes 216
9.5 Carcerands and hemicarcerands 217
9.6 Dendrimers 218
9.7 Pillar[n]arenes 221
9.8 Bambus[n]urils 222
9.9 Cyclophanes 223
9.10 Other miscellaneous molecular hosts 225
References 226
Chapter 10 Host-guest inclusion in mixed aqueous and nonaqueous solution 231
10.1 Introduction 231
10.2 Host-guest inclusion in mixed aqueous-organic solution 232
10.3 Host-guest inclusion in pure nonaqueous solution 234
10.3.1 Cyclodextrin inclusion complexes in nonaqueous solution 235
10.3.2 Inclusion complexes of other hosts in nonaqueous solution 237
10.4 Conclusions 238
References 238
Chapter 11 Applications of host-guest inclusion in solution 241
11.1 Analytical applications 241
11.2 Molecular sensors and molecular recognition 244
11.3 Control of guest reactivity 248
11.4 Medicinal and pharmaceutical applications 249
11.5 Water treatment and environmental remediation 252
11.6 Industrial applications 254
11.7 Other applications and summary 255
References 256
Chapter 12 Conclusions and summary 261
References 265
Index 267
