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Photochemistry and Photophysics: Concepts, Research, Applications

Photochemistry and Photophysics: Concepts, Research, Applications

Vincenzo Balzani, Paola Ceroni, Alberto Juris

ISBN: 978-3-527-67104-5

Mar 2014

504 pages

$66.99

Description

This textbook covers the spectrum from basic concepts of photochemistry and photophysics to selected examples of current applications and research.
Clearly structured, the first part of the text discusses the formation, properties and reactivity of excited states of inorganic and organic molecules and supramolecular species, as well as experimental techniques. The second part focuses on the photochemical and photophysical processes in nature and artificial systems, using a wealth of examples taken from applications in nature, industry and current research fields, ranging from natural photosynthesis, to photomedicine, polymerizations, photoprotection of materials, holography, luminescence sensors, energy conversion, and storage and sustainability issues.
Written by an excellent author team combining scientific experience with didactical writing skills, this is the definitive answer to the needs of students, lecturers and researchers alike going into this interdisciplinary and fast growing field.

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List of Boxes XVII

Preface XIX

Acknowledgments XXV

List of Abbreviations XXVII

1 Introduction 1

1.1 Photochemistry and Photophysics in Science and Technology 1

1.2 Historical Notes 2

1.3 A New Dimension of Chemistry and Physics 3

1.4 The Nature of Light 5

1.5 Absorption of Light 7

1.6 Quantum Yield, Efficiencies, and Excited-State Reactivity 8

References 10

2 Elementary Molecular Orbital Theory 11

2.1 Introduction 11

2.2 The Hydrogen Atom 11

2.3 Polyelectronic Atoms 13

2.4 From Atoms to Molecules 17

2.5 Electronic Structure of Homonuclear Diatomic Molecules 21

2.6 Electronic Structure of Heteronuclear Diatomic Molecules 25

2.7 Simple Polyatomic Molecules and Elements of Group Theory 26

2.7.1 Elements of Group Theory 26

2.7.2 Water 29

2.7.3 Ammonia 31

2.8 Typical Organic Molecules 33

2.8.1 Methane 33

2.8.2 Ethene 35

2.8.3 Benzene 37

2.8.4 Formaldehyde 39

2.9 Transition Metal Complexes 41

2.9.1 General Concepts 41

2.9.2 Typical Metal Complexes 48

References 52

3 Light Absorption and Excited-State Deactivation 55

3.1 Light Absorption 55

3.1.1 Selection Rules 57

3.1.2 Symmetry Selection Rules 58

3.1.3 Spin Selection Rules 59

3.1.4 The Franck–Condon Principle 60

3.1.5 Visualization of Photochemical Reactions on Potential Energy Surfaces 62

3.2 Jablonski Diagram 64

3.3 Excited-State Deactivation 68

3.3.1 Vibrational Relaxation 68

3.3.2 Radiationless Deactivation 68

3.3.3 Radiative Deactivation 71

3.3.4 Radiative Lifetime 72

3.4 Chemical Reactions 73

3.5 Kinetic Aspects 74

3.6 Solvent and Temperature Effects 75

3.6.1 Solvatochromic Shift 75

3.6.2 Crossing of States 77

3.6.3 Temperature Effects on Excited-State Lifetime 79

3.6.4 Thermally Activated Delayed Fluorescence 80

3.7 Selected Molecules 81

3.7.1 Oxygen 81

3.7.2 Naphthalene 83

3.7.3 Benzophenone 85

3.7.4 Zinc(II) Tetraphenyl Porphyrin 87

3.7.5 [Cr(en)3]3+ 90

3.7.6 [Co(NH3)6]3+ 92

3.7.7 [Ru(bpy)3]2+ 94

3.8 Semiconductors 96

References 100

4 Excited States: Physical and Chemical Properties 103

4.1 Excited State as a New Molecule 103

4.2 Lifetime 103

4.3 Energy 104

4.4 Geometry 105

4.4.1 Small Molecules 106

4.4.2 Ethene 107

4.4.3 Ethyne 108

4.4.4 Benzene 109

4.4.5 Formaldehyde 109

4.4.6 Square Planar Metal Complexes 111

4.5 Dipole Moments 112

4.6 Electron Transfer 114

4.7 Proton Transfer 117

4.8 Excimers and Exciplexes 120

References 122

5 From Molecules to Supramolecular Systems 125

5.1 Supramolecular (Multicomponent) Systems and Large

Molecules 125

5.2 Electronic Interaction in Mixed-Valence Compounds 127

5.3 Electronic Interaction in Donor–Acceptor Complexes 129

5.4 Electronic Stimulation and Electronic Interaction in the Excited State 131

5.5 Formation of Excimers and Exciplexes in Supramolecular Systems 134

References 136

6 Quenching and Sensitization Processes in Molecular and Supramolecular Species 139

6.1 Introduction 139

6.2 Bimolecular Quenching 140

6.2.1 Stern–Volmer Equation 140

6.2.2 Kinetic Details 143

6.2.3 Static versus Dynamic Quenching 144

6.2.4 Sensitized Processes 145

6.2.5 Spin Considerations 146

6.3 Quenching and Sensitization Processes in Supramolecular Systems 146

6.4 Electron-Transfer Kinetics 150

6.4.1 Marcus Theory 150

6.4.2 Quantum Mechanical Theory 153

6.4.2.1 The Electronic Factor 154

6.4.2.2 The Nuclear Factor 156

6.4.2.3 Optical Electron Transfer 156

6.5 Energy Transfer 157

6.5.1 Coulombic Mechanism 159

6.5.2 Exchange Mechanism 161

6.6 Role of the Bridge 163

6.7 Catalyzed Deactivation 164

References 166

7 Molecular Organic Photochemistry 169

7.1 Introduction 169

7.2 Alkenes and Related Compounds 169

7.2.1 Basic Concepts 169

7.2.2 Photoisomerization of Double Bonds 170

7.2.3 Electrocyclic Processes 172

7.2.4 Sigmatropic Rearrangements 173

7.2.5 Di-π-Methane Reaction 174

7.2.6 Photocycloaddition Reactions 174

7.2.7 Photoinduced Nucleophile, Proton, and Electron Addition 175

7.3 Aromatic Compounds 176

7.3.1 Introduction 176

7.3.2 Photosubstitution 179

7.3.3 Photorearrangement 180

7.3.4 Phototransposition 181

7.3.5 Photocycloadditions 181

7.4 Carbonyl Compounds 182

7.4.1 Introduction 182

7.4.2 Photochemical Primary Processes 183

7.5 Photochemistry of Other Organic Compounds 185

7.5.1 Nitrogen Compounds 185

7.5.1.1 Overview 185

7.5.1.2 Photoisomerization of Azocompounds 186

7.5.2 Saturated Oxygen and Sulfur Compounds 186

7.5.3 Halogen Compounds 187

References 189

8 Photochemistry and Photophysics of Metal Complexes 191

8.1 Metal Complexes 191

8.2 Photophysical Properties 191

8.3 Photochemical Reactivity 192

8.4 Relationships between Electrochemistry and Photochemistry 194

8.4.1 Cobalt (III) Complexes 195

8.4.2 Copper (I) Complexes 196

8.4.3 Ru(II) Polypyridine Complexes 196

8.4.4 Excited-State Redox Potentials 199

8.5 Luminescent Metal Complexes 201

8.5.1 Polypyridine Metal Complexes 201

8.5.2 Cyclometallated Complexes 203

8.5.2.1 Ruthenium Complexes 204

8.5.2.2 Rhodium Complexes 204

8.5.2.3 Iridium Complexes 205

8.5.2.4 Platinum Complexes 207

8.5.2.5 Orbital Nature of the Emitting Excited State 212

8.5.3 Porphyrin Complexes 213

8.5.4 Chromium (III) Complexes 216

8.5.5 Lanthanoid Complexes 219

8.6 Photochemical Processes 223

8.6.1 Types of Photoreactions 223

8.6.1.1 Photodissociation and Related Reactions 223

8.6.1.2 Photooxidation–Reduction Reactions 224

8.6.1.3 Intramolecular Rearrangements 225

References 226

9 Interconversion of Light and Chemical Energy by Bimolecular Redox Processes 231

9.1 Light as a Reactant 231

9.2 Light as a Product 232

9.3 Conversion of Light into Chemical Energy 233

9.4 Chemiluminescence 235

9.5 Electrochemiluminescence 235

9.6 Light Absorption Sensitizers 237

9.7 Light Emission Sensitizers 240

References 242

10 Light-Powered Molecular Devices and Machines 245

10.1 Molecules, Self-Organization, and Covalent Synthetic Design 245

10.2 Light Inputs and Outputs: Reading, Writing, and Erasing 246

10.3 Molecular Devices for Information Processing 247

10.3.1 Photochromic Systems as Molecular Memories 247

10.3.2 Molecular Logics 249

10.3.2.1 Luminescent Sensors as Simple Logic Gates 250

10.3.2.2 AND Logic Gate 251

10.3.2.3 XOR Logic Gate with an Intrinsic Threshold Mechanism 251

10.3.2.4 Encoding and Decoding 253

10.4 Molecular Devices Based on Energy Transfer 255

10.4.1 Wires 255

10.4.2 Switches 257

10.4.3 Plug/Socket Systems 258

10.4.4 Light-Harvesting Antennas 259

10.5 Molecular Devices Based on Electron Transfer 260

10.5.1 Wires 260

10.5.2 Switches 263

10.5.3 Extension Cables 265

10.6 Light-Powered Molecular Machines 268

10.6.1 Basic Remarks 268

10.6.2 The Role of Light 268

10.6.3 Rotary Motors Based on cis–trans Photoisomerization 269

10.6.4 Linear Motions: Molecular Shuttles and Related Systems 271

10.6.5 Photocontrolled Valves, Boxes, and Related Systems 275

References 276

11 Natural and Artificial Photosynthesis 281

11.1 Energy for Spaceship Earth 281

11.2 Natural Photosynthesis 284

11.2.1 Light Harvesting: Absorption and Energy Transfer 285

11.2.2 Photoinduced Electron Transfer Leading to Charge Separation 285

11.2.2.1 Bacterial Photosynthesis 285

11.2.2.2 Green Plants Photosynthesis: Photosystem II 287

11.2.3 Efficiency of Photosynthesis 288

11.3 Artificial Photosynthesis 290

11.3.1 Artificial Antenna 293

11.3.2 Artificial Reaction Centers 296

11.3.3 Coupling Artificial Antenna and Reaction Center 299

11.3.4 Coupling One-Photon Charge Separation with Multielectron Water Splitting 301

11.4 Water Splitting by Semiconductor Photocatalysis 302

References 304

12 Experimental Techniques 309

12.1 Apparatus 309

12.1.1 Light Sources 309

12.1.2 Monochromators, Filters, and Solvents 317

12.1.3 Cells and Irradiation Equipment 319

12.1.4 Detectors 321

12.2 Steady-State Absorption and Emission Spectroscopy 323

12.2.1 Absorption Spectroscopy 323

12.2.1.1 Instrumentation 324

12.2.1.2 Qualitative and Quantitative Applications 325

12.2.1.3 Sample Measurement 325

12.2.2 Emission Spectroscopy 326

12.2.2.1 Instrumentation 326

12.2.2.2 Emission Spectra 328

12.2.2.3 Excitation Spectra 329

12.2.2.4 Presence of Spurious Bands 330

12.2.2.5 Quantitative Relationship between Luminescence Intensity and Concentration 331

12.2.2.6 Stern–Volmer Luminescence Quenching 332

12.2.2.7 Emission Quantum Yields 333

12.3 Time-Resolved Absorption and Emission Spectroscopy 335

12.3.1 Transient Absorption Spectroscopy 335

12.3.1.1 Transient Absorption with Nanosecond Resolution 335

12.3.1.2 Transient Absorption with Femtosecond Resolution 337

12.3.2 Emission Lifetime Measurements 338

12.3.2.1 Single Flash 338

12.3.2.2 Gated Sampling 339

12.3.2.3 Upconversion Techniques 339

12.3.2.4 Single-Photon Counting 341

12.3.2.5 Data Analysis 342

12.3.2.6 Phase Shift 343

12.3.2.7 Luminescence Lifetime Standards 345

12.4 Absorption and Emission Measurements with Polarized Light 346

12.4.1 Linear Dichroism 346

12.4.2 Luminescence Anisotropy 347

12.5 Reaction Quantum Yields and Actinometry 349

12.5.1 Reaction Quantum Yields 349

12.5.2 Actinometry 350

12.5.2.1 Potassium Ferrioxalate 351

12.5.2.2 Potassium Reineckate 352

12.5.2.3 Azobenzene 353

12.6 Other Techniques 353

12.6.1 Photothermal Methods 353

12.6.1.1 Photoacoustic Spectroscopy 354

12.6.1.2 Photorefractive Spectroscopy 355

12.6.2 Single-Molecule Spectroscopy 357

12.6.3 Fluorescence Correlation Spectroscopy 358

12.6.4 X-ray Techniques 360

References 361

13 Light Control of Biologically Relevant Processes 365

13.1 Introduction 365

13.2 Vision 365

13.2.1 Basic Principle 365

13.2.2 Primary Photochemical Events 367

13.3 Light, Skin, and Sunscreens 367

13.4 Photochemical Damage in Living Systems 369

13.4.1 Photochemical Damage to DNA 369

13.4.2 Photochemical Damage to Proteins 369

13.5 Therapeutic Strategies Using Light 370

13.5.1 Phototherapy 370

13.5.2 Photochemotherapy of Psoriasis 370

13.5.3 Photodynamic Therapy 371

13.5.4 Photocontrolled Delivery 373

13.6 Photocatalysis in Environmental Protection 375

13.6.1 Principles 375

13.6.2 Solar Disinfection (SODIS) 375

13.6.3 Photoassisted Fenton Reaction 376

13.6.4 Heterogeneous Photocatalysis 376

13.7 DNA Photocleavage and Charge Transport 377

13.7.1 Photocleaving Agents of Nucleic Acid 377

13.7.2 Photoinduced Electron-Transfer Processes in DNA 378

13.8 Fluorescence 379

13.9 Bioluminescence 379

References 380

14 Technological Applications of Photochemistry and Photophysics 385

14.1 Introduction 385

14.2 Photochromism 385

14.3 Luminescent Sensors 388

14.3.1 Principles 388

14.3.2 Amplifying Signal 389

14.3.3 Wind Tunnel Research 389

14.3.4 Thermometers 391

14.3.5 Measuring Blood Analytes 393

14.3.6 Detecting Warfare Chemical Agents 395

14.3.7 Detecting Explosives 397

14.4 Optical Brightening Agents 399

14.5 Atmospheric Photochemistry 400

14.5.1 Natural Processes Involving Oxygen 400

14.5.2 Ozone Hole 401

14.6 Solar Cells 402

14.6.1 Inorganic Photovoltaic (PV) Cells 402

14.6.2 Organic Solar Cells (OSCs) 403

14.6.3 Dye-Sensitized Solar Cells (DSSCs) 405

14.7 Electroluminescent Materials 407

14.7.1 Light-Emitting Diodes (LEDs) 407

14.7.2 Organic Light-Emitting Diodes (OLEDs) 407

14.7.3 Light-Emitting Electrochemical Cells (LECs) 409

14.8 Polymers and Light 411

14.8.1 Photopolymerization 411

14.8.2 Photodegradation 411

14.8.3 Stabilization of Commercial Polymers 412

14.8.4 Photochemical Curing 413

14.8.5 Other Light-Induced Processes 413

14.8.6 Photolithography 414

14.8.7 Stereolithography 415

14.8.8 Holography 416

14.9 Light for Chemical Synthesis 417

14.9.1 Photochlorination of Polymers 418

14.9.2 Synthesis of Caprolactam 418

14.9.3 Synthesis of Vitamins 418

14.9.4 Perfumes 419

References 420

15 Green (Photo)Chemistry 425

15.1 Definition, Origins, and Motivations 425

15.2 Photochemistry for Green Chemical Synthesis 426

15.3 Photocatalysis 428

15.3.1 Heterogeneous Photocatalysis 428

15.3.2 Homogeneous Photocatalysis 429

15.4 Photocatalysis in Synthesis 429

15.4.1 Alkanes 430

15.4.2 Alkenes 430

15.4.3 Alkynes 432

15.4.4 Sulfides 432

15.5 Photocatalytic Pollution Remediation 433

15.6 Use of Solar Energy in Green Synthesis 434

References 436

16 Research Frontiers 439

16.1 Introduction 439

16.2 Aggregation-Induced Emission 439

16.3 Phosphorescence from Purely Organic Materials by Crystal Design 441

16.4 Synthesis of a 2D Polymer 443

16.5 Photocontrolled Relative Unidirectional Transit of a Nonsymmetric Molecular Wire through a Molecular Ring 444

16.6 Molecular Rotary Motors Powered by Visible Light via Energy Transfer 445

16.7 Cooperation and Interference in Multifunction Compounds 447

16.8 Singlet Fission 449

16.9 One-Color Photochromic System 452

16.10 Photonic Modulation of Electron Transfer with Switchable Phase Inversion 454

16.11 Dye-Sensitized Photoelectrosynthesis Cells (DSPECs) 457

References 459

Index 463

“This is a very timely book that provides an up to date presentation of photochemistry and photophysics in which the two subject areas are clearly interrelated.”  (Chemistry World, 14 October 2014)