Anion Coordination Chemistry

Written by the international anion coordination experts, this book includes all the recent advances in this emerging interdisciplinary field. The topics range from ion channels to selective sensors, making it attractive to all researchers and PhD students with an interest in supramolecular chemistry.

Preface XI

List of Contributors XIII

1 Aspects of Anion Coordination from Historical Perspectives 1
Antonio Bianchi, Kristin Bowman-James, and Enrique García-España

1.1 Introduction 1

1.2 Halide and Pseudohalide Anions 9

1.3 Oxoanions 23

1.4 Phosphate and Polyphosphate Anions 29

1.5 Carboxylate Anions and Amino Acids 36

1.6 Anionic Complexes: Supercomplex Formation 42

1.7 Nucleotides 51

1.8 Final Notes 60

References 60

2 Thermodynamic Aspects of Anion Coordination 75
Antonio Bianchi and Enrique García-España

2.1 Introduction 75

2.2 Parameters Determining the Stability of Anion Complexes 76

2.2.1 Type of Binding Group: Noncovalent Forces in Anion Coordination 76

2.2.2 Charge of Anions and Receptors 84

2.2.3 Number of Binding Groups 85

2.2.3.1 Additivity of Noncovalent Forces 86

2.2.4 Preorganization 87

2.2.4.1 Macrocyclic Effect 91

2.2.5 Solvent Effects 93

2.3 Molecular Recognition and Selectivity 102

2.4 Enthalpic and Entropic Contributions in Anion Coordination 110

References 132

3 Structural Aspects of Anion Coordination Chemistry 141
Rowshan Ara Begum, Sung Ok Kang, Victor W. Day, and Kristin Bowman-James

3.1 Introduction 141

3.2 Basic Concepts of Anion Coordination Chemistry 142

3.3 Classes of Anion Hosts 143

3.4 Acycles 144

3.4.1 Bidentate 144

3.4.2 Tridentate 149

3.4.3 Tetradentate 155

3.4.4 Pentadentate 161

3.4.5 Hexadentate 162

3.5 Monocycles 164

3.5.1 Bidentate 164

3.5.2 Tridentate 165

3.5.3 Tetradentate 166

3.5.4 Pentadentate 174

3.5.5 Hexadentate 175

3.5.6 Octadentate 177

3.5.7 Dodecadentate 179

3.6 Cryptands 181

3.6.1 Bidentate 181

3.6.2 Tridentate 183

3.6.3 Tetradentate 184

3.6.4 Pentadentate 186

3.6.5 Hexadentate 188

3.6.6 Septadentate 192

3.6.7 Octadentate 193

3.6.8 Nonadentate 197

3.6.9 Decadentate 198

3.6.10 Dodecadentate 199

3.7 Transition-Metal-Assisted Ligands 201

3.7.1 Bidentate 201

3.7.2 Tridentate 203

3.7.3 Tetradentate 204

3.7.4 Hexadentate 204

3.7.5 Septadentate 206

3.7.6 Dodecadentate 208

3.8 Lewis Acid Ligands 210

3.8.1 Transition Metal Cascade Complexes 210

3.8.2 Other Lewis Acid Donor Ligands 213

3.8.2.1 Boron-Based Ligands 213

3.8.2.2 Tin-Based Ligands 214

3.8.2.3 Hg-Based Ligands 216

3.9 Conclusion 218

Acknowledgments 218

References 218

4 Synthetic Strategies 227
Andrea Bencini and José M. Llinares

4.1 Introduction 227

4.2 Design and Synthesis of Polyamine-Based Receptors for Anions 227

4.2.1 Acyclic Polyamine Receptors 229

4.2.2 Tripodal Polyamine Receptors 234

4.2.3 Macrocyclic Polyamine Receptors with Aliphatic Skeletons 236

4.2.4 Macrocyclic Receptors Incorporating a Single Aromatic Unit 241

4.2.5 Macrocyclic Receptors Incorporating Two Aromatic Units 243

4.2.6 Anion Receptors Containing Separated Macrocyclic Binding Units 249

4.2.7 Cryptands 252

4.3 Design and Synthesis of Amide Receptors 258

4.3.1 Acid Halides as Starting Materials 259

4.3.1.1 Acyclic Amide Receptors 259

4.3.1.2 Macrocyclic Amide Receptors 267

4.3.2 Esters as Starting Materials 270

4.3.3 Using Coupling Reagents 276

References 279

5 Template Synthesis 289
Jack K. Clegg and Leonard F. Lindoy

5.1 Introductory Remarks 289

5.2 Macrocyclic Systems 290

5.3 Bowl-Shaped Systems 297

5.4 Capsule, Cage, and Tube-Shaped Systems 300

5.5 Circular Helicates and meso-Helicates 306

5.6 Mechanically Linked Systems 308

5.7 Concluding Remarks 314

References 315

6 Anion–p Interactions in Molecular Recognition 321
David Quiñonero, Antonio Frontera, and Pere M. Deyá

6.1 Introduction 321

6.2 Physical Nature of the Interaction 322

6.3 Energetic and Geometric Features of the Interaction Depending on the Host (Aromatic Moieties) and the Guest (Anions) 323

6.4 Influence of Other Noncovalent Interactions on the Anion–p Interaction 330

6.4.1 Interplay between Cation–p and Anion–p Interactions 330

6.4.2 Interplay between p-p and Anion–p Interactions 332

6.4.3 Interplay between Anion–p and Hydrogen-Bonding Interactions 334

6.4.4 Influence of Metal Coordination on the Anion–p Interaction 337

6.5 Experimental Examples of Anion–p Interactions in the Solid State and in Solution 338

6.6 Concluding Remarks 353

References 354

7 Receptors for Biologically Relevant Anions 363
Stefan Kubik

7.1 Introduction 363

7.2 Phosphate Receptors 364

7.2.1 Introduction 364

7.2.2 Phosphate, Pyrophosphate, Triphosphate 366

7.2.3 Nucleotides 387

7.2.4 Phosphate Esters 395

7.2.5 Polynucleotides 407

7.3 Carboxylate Receptors 410

7.3.1 Introduction 410

7.3.2 Acetate 412

7.3.3 Di- and Tricarboxylates 425

7.3.4 Amino Acids 433

7.3.5 Peptide C-Terminal Carboxylates 444

7.3.6 Peptide Side-Chain Carboxylates 450

7.3.7 Sialic Acids 451

7.4 Conclusion 453

References 453

8 Synthetic Amphiphilic Peptides that Self-Assemble to Membrane-Active Anion Transporters 465
George W. Gokel and Megan M. Daschbach

8.1 Introduction and Background 465

8.2 Biomedical Importance of Chloride Channels 466

8.2.1 A Natural Chloride Complexing Agent 468

8.3 The Development of Synthetic Chloride Channels 468

8.3.1 Cations, Anions, Complexation, and Transport 468

8.3.2 Anion Complexation Studies 470

8.3.3 Transport of Ions 470

8.3.4 Synthetic Chloride Transporters 470

8.4 Approaches to Synthetic Chloride Channels 471

8.4.1 Tomich’s Semisynthetic Peptides 472

8.4.2 Cyclodextrin as a Synthetic Channel Design Element 473

8.4.3 Azobenzene as a Photo-Switchable Gate 474

8.4.4 Calixarene-Derived Chloride Transporters 474

8.4.5 Oligophenylenes and p-Slides 477

8.4.6 Cholapods as Ion Transporters 479

8.4.7 Transport Mediated by Isophthalamides and Dipicolinamides 481

8.5 The Development of Amphiphilic Peptides as Anion Channels 481

8.5.1 The Bilayer Membrane 482

8.5.2 Initial Design Criteria for Synthetic Anion Transporters (SATs) 482

8.5.3 Synthesis of the N-Terminal Anchor Module 483

8.5.4 Preparation of the Heptapeptide 484

8.5.5 Initial Assessment of Ion Transport 485

8.6 Structural Variations in the SAT Modular Elements 488

8.6.1 Variations in the N-Terminal Anchor Chains 488

8.6.2 Anchoring Effect of the C-Terminal Residue 489

8.6.3 Studies of Variations in the Peptide Module 491

8.6.3.1 Structural Variations in the Heptapeptide 492

8.6.3.2 Variations in the Gly-Pro Peptide Length and Sequence 493

8.6.4 Variations in the Anchor Chain to Peptide Linker Module 494

8.6.5 Covalent Linkage of SATs: Pseudo-Dimers 496

8.6.6 Chloride Binding by the Amphiphilic Heptapeptides 498

8.6.7 The Effect on Transport of Charged Sidechains 499

8.6.8 Fluorescent Probes of SAT Structure and Function 500

8.6.8.1 Aggregation in Aqueous Suspension and in the Bilayer 501

8.6.8.2 Fluorescence Resonance Energy Transfer Studies 503

8.6.8.3 Insertion of SATs into the Bilayer 504

8.6.8.4 Position of SATs in the Bilayer 505

8.6.9 Self-Assembly Studies of the Amphiphiles 505

8.6.10 The Biological Activity of Amphiphilic Peptides 508

8.6.11 Nontransporter, Membrane-Active Compounds 509

8.7 Conclusions 509

Acknowledgments 509

References 510

9 Anion Sensing by Fluorescence Quenching or Revival 521
Valeria Amendola, Luigi Fabbrizzi, Maurizio Licchelli, and Angelo Taglietti

9.1 Introduction 521

9.2 Anion Recognition by Dynamic and Static Quenching of Fluorescence 522

9.3 Fluorescent Sensors Based on Anthracene and on a Polyamine Framework 529

9.4 Turning on Fluorescence with the Indicator Displacement Approach 538

9.4.1 Epilog 550

References 551

Index 553

Kristin Bowman-James received her Ph.D. in Chemistry at Temple University in Philadelphia, USA. Since 1987, she has been Professor at the University of Kansas, as well as being affiliated with several other universites. She is an experienced author with nearly 100 papers, many review articles and two books and has received numerous prizes.

Antonio Bianchi is Professor and Chairman at the Department of Chemistry at the University of Florence, Italy.

Enrique García-Espana is Professor at the Department of Inorganic Chemistry at the University of Valencia, Spain. He has worked within Supramolecular Chemistry since 1984 and has authored over 120 papers.