Mixed-Valence Systems: Fundamentals, Synthesis, Electron Transfer, and Applications

Cover
Title Page
Copyright
Contents
Preface
Chapter 1 Introduction and Fundamentals of Mixed‐Valence Chemistry
1.1 Introduction
1.2 Brief History
1.3 Diversity of Mixed‐Valence Systems – Some Examples
1.4 Characterization and Evaluation of Mixed‐Valence Systems
1.4.1 Electron Paramagnetic Resonance Spectroscopy
1.4.2 Electrochemical Methods
1.4.3 Optical Analysis
1.5 Important Issues in Mixed‐Valence Chemistry
1.5.1 System Transition in Mixed Valency from Localized to Delocalized
1.5.2 Solvent Control of Electron Transfer
1.6 Theoretical Background
1.6.1 Potential Energy Surfaces from Classical Two‐State Model
1.6.2 Quantum Description of the Potential Energy Surfaces
1.6.3 Reorganization Energies
1.6.4 Electronic Coupling Matrix Element and the Transition Moments
1.6.5 The Generalized Mulliken–Hush Theory (GMH)
1.6.6 Analysis of IVCT Band Shape
1.6.7 Rate Constant Expressions of Electron Transfer Reaction – The Marcus Theory
1.6.8 McConnell Superexchange Mechanism and the CNS Model
1.7 Conclusion and Outlook
Acknowledgments
References
Chapter 2 Conceptual Understanding of Mixed‐Valence Compounds and Its Extension to General Stereoisomerism
2.1 Introduction
2.2 Modeling MV and Related Chemistry
2.2.1 Origins Within Chemical Bonding Theory
2.2.2 Coupled Harmonic Oscillator Model
2.2.3 Intermolecular and Intramolecular Contributions to the Reorganization Energy
2.2.4 Effects of Electric Fields on MV Optical Band Shapes
2.2.5 Non‐adiabatic Effects
2.2.6 MV Complexes as Potential Quantum Qubits
2.2.7 Entanglement as a Measure of the Failure of the BO Approximation
2.2.8 Further Reading
2.3 Some Traditional Mixed‐Valence Example Molecules and Iconic Model Systems
2.3.1 Photochemical Charge Separation
2.3.2 MV Excited States in a Bis–Metal Complex
2.3.3 Hole Transport in a Molecular Conducting Material
2.3.4 Ground‐State Delocalization in the Creutz–Taube Ion
2.3.5 Photochemical Charge Separation During Bacterial Photosynthesis
2.3.6 Prussian Blue
2.4 Applications to Stereoisomerism
2.4.1 Breakdown of Aromaticity in the (π,π*) 3A1 Triplet Ground State of Pyridine
2.4.2 Isomerism of BNB
2.4.3 Isomerism of Ammonia and Related Molecules
2.4.4 Proton Transfer in [NH3·H·NH3]+
2.4.5 Aromaticity in Benzene
2.5 Conclusion and Outlook
References
Chapter 3 Quantum Chemical Approaches to Treat Mixed‐Valence Systems Realistically for Delocalized and Localized Situations
3.1 Introduction and Scope
3.2 How Did We Start
3.3 Moving to Transition Metal MV Systems, Getting into Conformational Aspects
3.4 More Recent Work on Organic MV Systems and More General Use for Charge Transfer Questions
3.5 More Recent Insights into Conformational Aspects for Transition Metal Complexes
3.6 Other Applications to Organometallic MV Systems
3.7 Limitations of the Simple Computational Protocols, Gas‐Phase Benchmarks, and Improved Electronic Structure Methods
3.8 More Advanced Treatments of Environmental Effects
3.9 Conclusion and Outlook
Acknowledgement
References
Chapter 4 Mixed Valency in Ligand‐Bridged Diruthenium Complexes
4.1 Introduction
4.2 RuIIRuIII Mixed‐Valent Systems
4.2.1 Pyrazine‐Derived Bridges
4.2.2 Other Bridging Ligands
4.3 RuIIIRuIV Mixed‐Valent Systems
4.4 RuIIRuI and RuIRu0 Mixed‐Valent Systems
4.5 Conclusion and Outlook
Acknowledgment
References
Chapter 5 Electronic Communication in Mixed‐Valence (MV) Ethynyl, Butadiynediyl, and Polyynediyl Complexes of Iron, Ruthenium, and Other Late Transition Metals
5.1 Introduction
5.2 Iron–Ethynyl Complexes
5.2.1 Dinuclear Iron–Ethynyl Complexes with Butadiynediyl Bridge
5.2.2 Dinuclear Iron–Ethynyl Complexes with Diynediyl, Polycyclic Aromatic Hydrocarbons and Heterocycles in the C4 Bridge Core
5.2.3 Dinuclear Iron–Ethynyl Complexes with Non‐conjugated C4 Bridge Core
5.2.4 Functionalized Dinuclear Iron–Ethynyl Complexes
5.3 Ruthenium–Ethynyl Complexes
5.3.1 Dinuclear Ruthenium–Ethynyl Complexes with Cp′(L2)Ru‐Based Termini
5.3.2 Dinuclear Ruthenium–Ethynyl Complexes with Ru(dppe)2X‐Based Termini
5.3.3 Ruthenium–Ethynyl Complexes with Alternating Polyyndiyl and Capped Ru–Ru Units
5.3.4 Ruthenium–Ethynyl Complexes with Other Ruthenium–Ethynyl Termini and Core Units
5.4 Other Transition Metal–Ethynyl Complexes
5.4.1 Dinuclear Group 6 (Cr and Mo) Metal–Ethynyl Complexes
5.4.2 Dinuclear Group 7 (Mn and Re) Metal–Polyynediyl Complexes
5.4.3 Dinuclear Group 8 (Os) and Group 9 (Co) Metal–Polyyndiyl Complexes
5.5 Concluding Remarks and Outlook
Acknowledgment
References
Chapter 6 Electron Transfer in Mixed‐Valence Ferrocenyl‐Functionalized Five‐ and Six‐Membered Heterocycles
6.1 Introduction
6.2 Ferrocenyl‐Functionalized Five‐Membered Heterocycles
6.2.1 Five‐Membered Heterocyclic Compounds with Group 13 Elements
6.2.2 Five‐Membered Heterocyclic Compounds with Group 14 Elements
6.2.3 Five‐Membered Heterocyclic Compounds with Group 15 Elements
6.2.4 Five‐Membered Heterocyclic Compounds with Group 16 Elements
6.2.5 Five‐Membered Heterocyclic Compounds with Transition Metal Elements
6.3 Ferrocenyl‐Functionalized Six‐Membered Heterocycles
6.4 Conclusion and Outlook
Acknowledgment
References
Chapter 7 Electronic Coupling and Electron Transfer in Mixed‐Valence Systems with Covalently Bonded Dimetal Units
7.1 Introduction
7.2 Synthesis and Characterization
7.3 d(δ)(M2)‐p(π)(Ligand) Conjugation
7.4 Electronic and Intervalence Transitions and DFT Calculations
7.5 Transition in Mixed Valency Between Robin–Day Classes
7.6 Distance Dependence of Electronic Coupling and Electron Transfer
7.7 Conformational Effects of Electronic Coupling and Electron Transfer
7.8 Class III and Beyond
7.9 Cross‐Conjugation and Quantum Destructive Effect
7.10 Electronic Coupling and Electron Transfer Across Hydrogen Bonds
7.11 Mixed‐Valence Diruthenium Dimers
7.12 Conclusions and Outlook
Acknowledgments
References
Chapter 8 Mixed‐Valence Electron Transfer of Cyanide‐Bridged Multimetallic Systems
8.1 Introduction
8.2 Dinuclear Cyanide‐Bridged Mixed‐Valence Complex
8.3 Trinuclear Cyanide‐Bridged Mixed‐Valence Complex
8.4 Tetranuclear and Higher Nuclear Cyanide‐Bridged Mixed‐Valence Complex
8.5 Conclusion and Outlook
Acknowledgment
References
Chapter 9 Organic Mixed‐Valence Systems: Toward Fundamental Understanding of Charge/Spin Transfer Materials
9.1 A Brief Sketch of the History of Organic Mixed‐Valence Systems
9.2 A Glossary for This Chapter
9.2.1 Hush Analysis
9.2.2 Mulliken–Hush Two‐State Analysis
9.2.3 Mulliken–Hush Two‐Mode Analysis
9.2.4 Generalized Mulliken–Hush Three‐State Analysis
9.3 Relationship Between Bridging Units and Electronic Coupling
9.4 Where to Attach Redox Centers
9.5 Through‐Bond or Through‐Space?
9.6 Control of Spin States Through Mixed‐Valence States
9.7 Future Prospects
Acknowledgment
References
Chapter 10 Mixed‐Valence Complexes in Biological and Bio‐mimic Systems
10.1 Introduction
10.2 Mixed‐Valence Iron–Sulfur Clusters in Biological and Bio‐mimic Systems
10.2.1 Basic FeS Clusters
10.2.2 [FeFe]‐Hydrogenase
10.2.3 Nitrogenases
10.2.4 Carbon Monoxide Dehydrogenase
10.3 Mixed‐Valence Systems in Multiheme and Other Multiiron‐Contained Biological Systems and Their Mimics
10.4 Mixed‐Valence Multicopper Cofactors in Biological and Mimicking Systems
10.5 OEC and Other Mixed‐Valence Multimanganese Cofactors
10.6 Summary
Acknowledgement
References
Chapter 11 Control of Electron Coupling and Electron Transfer Through Non‐covalent Interactions in Mixed‐Valence Systems
11.1 Introduction
11.2 Electronic Coupling Through Hydrogen Bonds
11.2.1 Electronic Coupling Between Transition Metal Centers Through Hydrogen Bonds
11.2.2 Electronic Coupling Between Organic Fragments Through Hydrogen Bonds
11.3 Modulation of Electronic Coupling via Host–Guest or Through‐Space Interaction
11.4 Conclusion
Acknowledgment
References
Chapter 12 Stimulus‐Responsive Mixed‐Valence and Related Donor–Acceptor Systems
12.1 Introduction
12.2 Photoswitchable Compounds
12.3 Anion‐Responsive Compounds
12.4 Proton‐Responsive Compounds
12.5 Conclusion and Outlook
Acknowledgement
References
Chapter 13 Mixed Valency in Extended Materials
13.1 Introduction
13.1.1 Fundamental Aspects of Mixed Valency in the Solid State
13.1.2 Quantum Mechanical Considerations in Mixed Valency and IVCT
13.1.3 Marcus–Hush Theory and the Quantification of CT
13.1.4 Classifications of Mixed Valency
13.1.5 Organic Mixed Valency
13.2 Electron Transfer in Extended MV Materials
13.2.1 Introduction to Extended Materials
13.2.2 Organic‐Based Mixed Valency in Extended Frameworks
13.2.2.1 Thiazolo[5,4‐d]thiazole‐Based Compounds
13.2.2.2 Tetrathiafulvalene (TTF)‐Based Compounds
13.2.2.3 Tetraoxolene‐Based Compounds
13.2.2.4 Naphthalenediimide (NDI)‐Based Compounds
13.2.2.5 Phenalenyl‐Based Compounds
13.2.2.6 Covalent‐Organic Frameworks (COFs)
13.2.3 Metal‐Based Mixed Valency
13.2.3.1 First‐Row Transition Metals
13.2.3.2 Other Metals
13.2.3.3 Catalysis in Uncoupled MV Systems
13.3 Conclusion
References
Chapter 14 Near‐Infrared Electrochromism Based on Intervalence Charge Transfer
14.1 Introduction
14.2 Near‐Infrared Electrochromic Materials
14.2.1 Inorganic NIR Electrochromic Materials
14.2.2 Organic NIR Electrochromic Materials
14.2.2.1 Viologen Derivatives
14.2.2.2 Triphenylamine Derivatives
14.2.2.3 Organic Conducting Polymers
14.2.2.4 Covalence‐Organic Framework (COF)
14.2.3 Organic–Inorganic Hybrid NIR Electrochromic Materials
14.2.3.1 Metal Complexes
14.2.3.2 Conducting Polymers of Metal Complexes
14.2.3.3 Monolayer and Multilayer Assembled Films
14.3 Potential Applications of NIR Electrochromic Materials
14.3.1 Smart Windows
14.3.2 Molecular Logic Gates and Optical Storage
14.3.3 Optical Communication
14.3.4 Military Camouflage
14.4 Summary and Outlook
Acknowledgment
References
Chapter 15 Manipulation of Metal‐to‐Metal Charge Transfer Toward Switchable Functions
15.1 Introduction
15.2 Switchable Cyanide‐Bridged MMCT Systems
15.3 Cyanide‐Bridged MMCT Complexes Showing Switchable Functional Properties
15.3.1 Modulating Molecular Nanomagnet Behavior
15.3.2 Modulating Molecular Electric Dipole
15.3.3 Modulating Thermal Expansion Behavior
15.3.4 Modulating Photochromic Behavior
15.4 Conclusion and Outlook
References
Index
EULA