Iridium(III) in Optoelectronic and Photonics Applications, 2 Volume Set

Edited byEli Zysman-Colman EaStCHEM School of Chemistry, University of St Andrews, UK

• List of Contributors xvForeword xviiPreface xixVOLUME 11 Archetypal Iridium(III) Compounds for Optoelectronic and Photonic Applications: Photophysical Properties and Synthetic Methods 1Joseph C. Deaton and Felix N. Castellano1.1 Introduction 11.2 Iridium Complex Ion Dopants in Silver Halide Photographic Materials 11.3 Overview of the Photophysical Properties of C^N and C^C: Cyclometalated Ir(III) Complexes 21.4 Importance of Ir─C Bonds in the Archetypal Ir(III) Complexes for Optoelectronic and Photonic Applications 91.5 Tuning Emission Color 141.6 Absorbance and Photoluminescence of C^N Cyclometalated Ir(III) Complexes 171.7 SOC Mechanism: Radiative Decay Rates and ZFS 231.8 Non-Radiative Decay Rates 391.9 Synthetic Methods Targeting C^N Cyclometalated Ir(III) Compounds 421.10 Synthetic Methods for Cyclometalated Ir(III) Compounds Containing Carbenes 471.11 Conclusions 48Acknowledgements 49Abbreviations for Ligands in Ir(III) Complexes 49References 502 Multinuclear Iridium Complexes 71J. A. Gareth Williams2.1 Introduction 712.2 Compounds Incorporating ‘Single Atom Bridges’: μ-Chloro, μ-Oxo and μ-Aza 722.2.1 μ-Chloro-Bridged Complexes 722.2.2 μ-Aza-Bridged Complexes 742.2.3 μ-Hydroxo-Bridged Complexes 762.3 Polyatomic Acyclic Bridges: Acetylides, Cyanides and Hydrazides 782.4 Compounds with Heterocyclic Bridges 822.4.1 Bis-(N^N)-Coordinating Ligands and Related Systems Incorporating At Least One N^N Unit 832.4.2 Bis-(N^C)-Coordinating Ligands 892.5 Multinuclear Complexes Featuring Conjugated Bridges between Iridium-Bound Polypyridyl or Arylpyridyl Ligands 932.5.1 Systems Incorporating C≡C or N=N Bridges with One or More [Ir(N^C)2(N^N)]+ Units 952.5.2 Multinuclear Complexes Incorporating Phenyl and Polyphenylene Bridges between the Ligands: ‘Supramolecular Assemblies’ 962.6 Concluding Remarks 104Acknowledgements 104References 1043 Soft Materials and Soft Salts Based on Iridium Complexes 111Etienne Baranoff and Yafei Wang3.1 Introduction 1113.2 Liquid Crystals 1123.3 Gels 1153.4 Micelles 1163.5 Langmuir–Blodgett Films 1183.6 Soft Salts 1183.7 Conclusion 123Acknowledgements 123References 1234 Porous Materials Based on Precious Metal Building Blocks for Solar Energy Applications 127Daniel Micheroni and Wenbin Lin4.1 Introduction 1274.2 The Luminescent Nature of MOFs and Their Use in Chemical Applications 1294.3 Energy Transfer in Porous Materials 1344.4 Porous Materials for Water Oxidation 1364.5 Porous Materials for Proton Reduction 1384.6 Porous Materials for CO2 Reduction 1404.7 Conclusions and Outlook 141References 1415 Polymeric Architectures Containing Phosphorescent Iridium(III) Complexes 145Andreas Winter and Ulrich S. Schubert5.1 Introduction 1455.2 Ir(III)-Containing Polymers: Classification, Design Principles, and Syntheses 1465.2.1 Classification of Ir(III)-Containing Polymers 1465.2.2 Design Principles for Metal-Containing Polymers 1475.2.2.1 Decoration of Preformed Polymers with Ir(III) Complexes 1495.2.2.2 Coordination of Ir(III) Precursor Complexes to Preformed Polymers 1515.2.2.3 (Co)Polymerization of Ir(III)-Containing Monomers 1575.2.2.4 Electropolymerization of Ir(III)-Containing Complexes 1825.2.2.5 Synthetic Approaches Toward Ir(III)-Containing Polymers: The Roads Not Taken 1865.3 Hyperbranched and Dendritic Architectures 1875.3.1 Ir(III)-Containing Hyperbranched Polymers 1875.3.2 Ir(III)-Containing Dendritic Systems 1885.4 Concluding Remarks 191References 1926 Iridium(III) Complexes for OLED Application 205Elena Longhi and Luisa De Cola6.1 Introduction 2056.2 Iridium Complexes 2066.2.1 General Synthesis of Ir(III) Complexes 2076.2.2 Luminescence of Iridium(III) Complexes 2086.2.3 Emission Color Tuning in Iridium(III) Complexes 2096.2.3.1 Influence of the (C^N) Ligand 2106.2.3.2 Influence of the Ancillary Ligand 2126.3 Organic Light-Emitting Diodes 2166.3.1 Device Architecture and Fabrication 2176.3.2 Device Lifetime 2186.3.3 Device Efficiency 2206.3.4 Phosphorescent Materials 2216.3.5 Host Materials 2226.4 Iridium(III) Complexes for PHOLED Application 2276.4.1 Green Emitters 2276.4.1.1 Role of the Ancillary Ligand 2286.4.1.2 Modification of the Phenylpyridine Ring 2296.4.1.3 Use of Different Tris-cyclometalated Motifs 2306.4.2 Red Emitters 2326.4.3 Blue Emitters 2386.5 Conclusions and Perspectives 262References 2627 A Comprehensive Review of Luminescent Iridium Complexes Used in Light-Emitting Electrochemical Cells (LEECs) 275Adam F. Henwood and Eli Zysman-Colman7.1 Introduction 2757.2 Device Fundamentals 2787.3 Green Emitters 2807.3.1 Archetypal Emitters 2827.3.2 Pyrazoles 2897.3.3 Imidazoles 2927.3.4 Triazoles and Tetrazoles 2937.3.5 Oxadiazoles 2947.3.6 Thiophenes 2967.3.7 Intramolecular π-Stacked Emitters 2967.3.8 Supramolecular Emitters 3007.4 Blue Emitters 3017.4.1 [Ir(ppy)2(bpy)]+-Type Emitters 3027.4.2 Pyrazoles 3077.4.3 Imidazoles 3127.4.4 Triazoles 3137.4.5 Oxadiazoles 3167.4.6 N-Heterocyclic Carbenes 3207.4.7 Phosphines 3227.5 Yellow Emitters 3237.5.1 [Ir(ppy)2(bpy)]+-Type Emitters 3247.5.2 Imidazole Emitters 3277.5.3 Anionic Emitters 3287.5.4 Intramolecularly π-Stacked Emitters 3287.5.5 Multifunctional or Supramolecular Emitters 3327.6 Orange-Red Emitters 3347.6.1 [Ir(ppy)2(bpy)]+-Type Emitters 3357.6.2 Emitters Bearing Five-Membered Heterocyclic Rings 3407.6.3 Intramolecular π-Stacked Emitters 3417.6.4 Multifunctional Emitters 3457.7 Conclusions and Outlook 348Acknowledgements 349References 349VOLUME 28 Electrochemiluminescence of Iridium Complexes 359Sarah E. Laird and Conor F. Hogan8.1 Background and Overview of Electrochemiluminescence 3598.1.1 ECL from Metal Complexes 3628.2 Iridium ECL 3638.2.1 First Examples 3638.2.2 Renewed Interest in Iridium ECL Stimulated by Progress in the Field of Light-Emitting Devices 3648.2.3 Early Advances in Theoretical Understanding and Electrochemiluminophore Design 3668.2.4 Modified Electrode Systems 3708.2.5 ECL-Based Sensing Strategies 3728.2.6 Issues Related to ECL of Iridium Complexes in Aqueous Media and Quenching by Oxygen 3848.2.7 Tuning ECL Emission Colour and Redox Properties 3868.2.8 Potential-Resolved Multicolour ECL 3998.2.8.1 Miscellaneous ECL Systems Involving Iridium Complexes 4058.2.9 Conclusion and Future Prospects 406List of Ligand Abbreviations Used in Text 406References 4079 Strategic Applications of Luminescent Iridium(III) Complexes as Biomolecular Probes, Cellular Imaging Reagents, and Photodynamic Therapeutics 415Karson Ka-Shun Tso and Kenneth Kam-Wing Lo9.1 Introduction 4159.2 General Cellular Staining Reagents 4169.3 Hypoxia Sensing Probes 4239.4 Molecular and Ion Intracellular Probes 4279.4.1 Intracellular Probes for Sulfur-Containing Species 4279.4.2 Intracellular Probes for Metal Ions 4339.4.3 Intracellular Probes for Hypochlorous Acid and Hypochlorite 4379.4.4 Intracellular Probes for Nitric Oxide 4399.5 Organelle-Targeting Bioimaging Reagents 4419.5.1 Nucleus 4419.5.2 Nucleoli 4439.5.3 Golgi Apparatus 4459.5.4 Mitochondria 4479.6 Functionalized Polypeptides for Bioimaging 4509.7 Polymers and Nanoparticles for Bioimaging 4549.8 Photocytotoxic Reagents and Photodynamic Therapeutics 4589.9 Conclusion 466Acknowledgements 466Abbreviations 466References 46910 Iridium Complexes in the Development of Optical Sensors 479Teresa Ramón-Márquez, Marta Marín-Suárez, Alberto Fernández-Gutiérrez and J. F. Fernández-Sánchez10.1 Generalities of Optical Sensors 47910.2 Ir(III) Used as Optical Probes 48110.2.1 Optical Probes for the Detection of Gaseous Species 48110.2.1.1 Oxygen 48210.2.1.2 Other Gaseous Species 48310.2.2 Optical Probes for the Detection of Ionic Species 48510.2.2.1 Cations 48510.2.2.2 pH 49110.2.2.3 Anions 49310.2.3 Optical Probes for the Detection of Biomolecules 49810.2.3.1 Amino Acids and Proteins 49810.2.3.2 Nucleotides and Nucleic Acids 50610.2.4 Optical Probes for the Detection of Other Small Molecules 50610.2.4.1 Explosives 50610.2.4.2 Free Radicals 50710.2.4.3 H2O2 50810.2.4.4 Amines 50810.2.4.5 Silver Salts 50810.2.4.6 Hypochlorous Acid (HOCl) 50810.3 Ir(III) Used in the Development of Sensing Phases 50910.3.1 Sensing Phases for the Detection of Gases 50910.3.1.1 Oxygen 50910.3.1.2 Others Gases 51610.3.2 Sensing Phases for the Detection of Ions 51610.3.3 Sensing Phases for the Detection of Biomolecules 51710.3.3.1 Glucose 51810.3.3.2 BSA 52010.3.3.3 Cysteine and Homocysteine 52010.3.3.4 Heparin 52010.3.3.5 Histone 52110.3.4 Sensing Phases for Multiparametric Sensing 52110.4 Conclusion and Future Challenges 522Acronyms Used in the Names of the Complexes 525References 52811 Photoredox Catalysis of Iridium(III)-Based Photosensitizers 541Timothy M. Monos and Corey R. J. Stephenson11.1 Introduction 54111.1.1 Photoredox Catalysis 54111.1.2 Principles of Photoredox Catalysis 54211.1.3 Iridium(III) Photocatalyst Design 54211.1.4 Ir(III) Photocatalyst synthesis 54511.2 Iridium-Based Photoredox Catalysis in Organic Synthesis 54711.2.1 Net Oxidative Reactions 54711.2.1.1 Amine Oxidation and Functionalization 54711.2.1.2 Arene Oxidation 55111.2.2 Net Reductive Reactions 55111.2.2.1 Dehalogenation Reactions 55111.2.2.2 Ketyl Radical Chemistry 55311.2.3 Redox-Neutral Reactions 55411.2.3.1 Atom Transfer Radical Addition 55511.2.3.2 Radical-Based Arene Addition Reactions 56111.2.3.3 Tandem Catalysis Methods 56511.2.4 Amine Fragmentation 57111.3 Conclusion 574References 57412 Solar Fuel Generation: Structural and Functional Evolution of Iridium Photosensitizers 583Husain N. Kagalwala, Danielle N. Chirdon and Stefan Bernhard12.1 Introduction 58312.2 Fundamentals of [Ir(C^N)2(N^N)]+ Photosensitizers 58512.2.1 Synthesis and Structure 58512.2.2 Electronics: Photophysics and Electrochemistry 58512.2.3 Complexes Made to Order 58812.3 Application of [Ir(C^N)2(N^N)]+ in Photocatalytic Water Reduction 58912.3.1 Initial Exploration 58912.3.2 Systems with Non-precious Components 59112.3.3 Strategies for Improved Efficiency 59412.3.3.1 New C^N Ligands 59412.3.3.2 New N^N Ligands 59712.3.3.3 Orchestration 59912.4 Alternative Iridium Structures 60312.4.1 Tridentate Coordination 60312.4.2 Tris-Cyclometalated Complexes 60512.4.3 Dinuclear Iridium Complexes 60612.5 Outlook 607Acknowledgements 609References 61013 Iridium Complexes in Water Oxidation Catalysis 617Ilaria Corbucci, Alceo Macchioni and Martin Albrecht13.1 Introduction 61713.2 Sacrificial Oxidants 61913.2.1 Cerium(IV) Ammonium Nitrate 62013.2.2 Sodium Periodate 62013.3 Molecular Iridium Catalyst for Water Oxidation 62113.3.1 Ir WOCs without Cp∗ 62113.3.2 Ir WOCs with Cp∗ 62413.3.3 Cp∗Ir WOCs Based on Carbene-Type Ligands 63213.3.3.1 Cp∗Ir WOCs Bearing Normal Carbene-Type Ligands 63313.3.3.2 Cp∗Ir WOCs Bearing Abnormal Carbene-Type Ligands 63613.3.3.3 Comparison of Catalytic Activity of Cp∗Ir Bearing Mesoionic Imidazolylidene Ligand or the Mesoionic Triazolylidene Analogue 63813.3.4 Heterogenized Molecular Iridium Catalyst for Water Oxidation 64013.3.5 Iridium WOC as Photocatalyst for Water Oxidation under Visible Light Irradiation 64513.4 Conclusions 647Acknowledgements 648Glossary of Terms and Abbreviations 648References 64914 Iridium Complexes as Photoactive Center for Light Harvesting and Solar Cell Applications 655Etienne Baranoff and Prashant Kumar14.1 Introduction 65514.2 Photoinduced Electron Transfer in Multicomponent Arrays 65614.2.1 Ir(tpy)2 Fragment (tpy = 2,2 :6 -2 -terpyridine) 65614.2.2 Cyclometalated Iridium(III) 66014.3 Iridium Complexes as Photoactive Center for Solar Cell Applications 66514.3.1 Sensitizer for Dye-Sensitized Solar Cells 66514.3.2 Iridium Complexes for Organic Photovoltaic Devices 67314.4 Conclusions 676References 677Index 683