The Cation-π Interaction

Description

This book introduces the role of cation–π interactions in chemistry, biology, and polymer materials science. Since the cation–π interaction was defined in 1990, its importance has been recognized in a variety of fields due to its relatively significant interaction energy. A number of examples are introduced in which the contribution of cation–π interactions was evidenced by X-ray structures, spectroscopies, computations, and other means. The latest developments in these areas are remarkable; therefore, many recent examples are included.As this book covers the basic aspects of the applications of cation–π interactions it is useful for students and researchers in a wide variety of scientific fields. In addition, the book will not only facilitate understanding of the phenomena occurring in various systems but also provides insights into the design of new catalysts, reactions, and materials. Cover Half Title The Cation–π Interaction Copyright Preface Contents 1. Introduction 1.1 Non-covalent Interaction 1.2 Cation–π Interaction References 2. Fundamentals of Cation–π Interactions 2.1 Metal Ions 2.1.1 Alkali Metal Ions 2.1.2 Alkaline Earth Metal Ions 2.1.3 Transition Metal Ions 2.2 Organic Cations 2.2.1 Structural Diversity 2.2.2 Pyridinium Ions 2.2.3 Quaternary Ammonium Ions 2.2.4 Guanidinium Ions 2.3 π-Systems 2.3.1 Aromatic Rings 2.3.2 Alkenes and Alkynes 2.3.3 Carbonyl and Thiocarbonyl Groups 2.4 Factors Affecting Interactions 2.4.1 Solvent Effect 2.4.2 Counter-Anion Effect 2.4.3 Directional Dependence 2.5 Cooperation Among Non-covalent Interactions 2.5.1 Ternary Systems 2.5.2 Multiple Systems 2.5.3 Cooperation with Hydrogen Bonds 2.5.4 Cooperation with Halogen Bonds References 3. Biological Systems 3.1 Protein Structure 3.1.1 PDB Analysis of Protein Structures 3.1.2 α-Helix 3.1.3 β-Hairpin 3.1.4 Miniature Proteins 3.1.5 pH Dependence on Protein Conformation 3.2 Protein–Protein Association 3.2.1 PDB Analysis of Protein–Protein Interfaces 3.2.2 Helix–Helix Association 3.2.3 Self-Assembly of Collagen-Mimetic Peptides 3.2.4 Dissociation of UVR8 Homodimer 3.3 Protein–DNA Association 3.3.1 PDB Analysis of Protein–DNA Complexes 3.3.2 Nuclear Cap-Binding Complexes 3.4 Protein–Ligand Association 3.4.1 Recognition of Quaternary Ammonium Ions 3.4.2 Biosynthesis of Aristolochene 3.4.3 Cellulase–Lignin Association 3.4.4 Recognition of Purine Analogues 3.5 Ion Channels 3.5.1 Ligand-Gated Ion Channels 3.5.2 Voltage-Gated Ion Channels References 4. Organic Synthesis 4.1 Role of Cation–π Interactions in Organic Reactions 4.2 Organic Cations 4.2.1 Pyridinium and Heteroaromatic Cations 4.2.2 Iminium Ions 4.2.3 Oxonium Ions 4.2.4 Carbocations 4.2.5 Quaternary Ammonium Ions 4.3 Alkali Metal Ions 4.3.1 Lithium Ion 4.3.2 Sodium Ion 4.3.3 Potassium Ion 4.4 Supramolecular Systems 4.4.1 Cyclophanes 4.4.2 Supramolecular Cages 4.5 Solid-State Reactions 4.5.1 Photocyclization 4.5.2 Gas–Solid Reactions 4.6 Biocatalysis 4.6.1 Enzymes 4.6.2 Catalytic Antibodies References 5. Materials Science 5.1 Polymers 5.1.1 Supramolecular Polymers and Oligomers 5.1.2 Surface Modification of Polymers 5.1.3 Indole-Based Hydrogels 5.2 Biopolymer and Biomimetic Polymers 5.2.1 Mussel Underwater Adhesion 5.2.2 Mussel-Inspired Polymers 5.2.3 Lignin Biopolymers 5.3 Graphene-Based Materials 5.3.1 Graphene Oxide Membranes 5.3.2 Adsorption of Cationic Molecules 5.3.3 Dispersion of Graphenes 5.3.4 Formation of Non-Stoichiometric NaxCl Crystals 5.4 Energy-Related Materials 5.4.1 Energy Generation Systems 5.4.2 Energy Storage Systems 5.5 Fluorophores 5.5.1 Fluorescent-Switch Polymers 5.5.2 HaloTag Fluorogenic Probes 5.5.3 Sensors for Alkyl Halides 5.5.4 Aggregation-Induced Emission Luminogens 5.5.5 Intercalation-Induced Emission Systems 5.6 Recognition-Based Materials 5.6.1 Cavitand Receptors for AFM Prove Recognition 5.6.2 Sumanene–Ferrocene Conjugates for Cs+ Recognition References