Cover -- Title Page -- Copyright -- Contents -- Foreword -- Preface -- Part I Interplay of Light and Matter -- Chapter 1 Physicochemical Aspects of Photoswitching -- 1.1 Introduction -- 1.2 Essentials of Photophysics -- 1.2.1 Quantum Yield -- 1.2.2 Photostationary State -- 1.2.3 Photoactivation -- 1.3 Spectroscopy of Photoswitching -- 1.4 Two Case Examples -- 1.4.1 Diarylethenes -- 1.4.2 Azobenzene and Its Derivatives -- References -- Chapter 2 Computational Methods and Photochromism -- 2.1 Introduction -- 2.2 Basics of Computational Photochemistry -- 2.2.1 Electronic Structure Methods -- 2.2.2 Photochemical Pathway and Conical Intersections -- 2.3 Applications: Photoswitching Mechanisms of Photochromic Compounds -- 2.3.1 Dihydroazulene Photochromism -- 2.3.2 Dihydropyrene Photochromism -- 2.4 Conclusions and Perspectives -- References -- Part II Chemical Classes of Molecular Photoswitches -- Chapter 3 Azobenzenes: The Quest for Visible Light Triggering -- 3.1 Introduction -- 3.1.1 Azobenzene and Its Physical Characteristics -- 3.2 Synthesis of Azobenzenes -- 3.2.1 Synthesis of Symmetrical Azobenzenes by Oxidation of Anilines -- 3.2.2 Azo Coupling -- 3.2.3 Mills Reaction -- 3.2.4 Modern Methods -- 3.3 Visible Light-Activated Azobenzenes as Photoswitches -- 3.3.1 The Effect of Electron-Donating Groups on Direct Photoexcitation -- 3.3.2 The Effect of Electron-Withdrawing Groups on Direct Photoexcitation -- 3.3.3 Further Modification Leading to Visible Light Photoswitches -- 3.3.4 Complex Molecular and Supramolecular Systems Containing Azobenzenes -- 3.4 Applications of Azobenzenes in Biological Systems -- 3.5 Conclusion -- References -- Chapter 4 Diazocines: Photoswitches with Excellent Photophysical Properties and Inverted Stabilities -- 4.1 Photophysical Properties and Conformations of Parent Diazocine -- 4.2 Synthesis of Diazocines.

11.2.4 Third-Generation Rotary Molecular Motors -- 11.3 Dynamics and Kinetics of Molecular Motors -- 11.3.1 Thermal Isomerization -- 11.3.2 Tuning the Speed of Rotation -- 11.3.3 Photoisomerization -- 11.3.4 Tuning the Absorption Wavelength -- 11.3.5 Photochemical Motors -- 11.3.6 Novel Motor Core Designs -- 11.4 Applications -- 11.4.1 Transfer of Chirality -- 11.4.2 Transfer of Motion -- 11.4.2.1 Coupled Rotary Systems -- 11.4.2.2 Translation of Motion -- 11.4.2.3 Control Over Motion -- 11.4.3 Biological Applications -- 11.4.4 Other Applications -- 11.5 Perspective and Outlook -- References -- Chapter 12 Stilbenes Revisited: Understanding the Mechanism of Mechanochemical Coupling -- 12.1 Introduction -- 12.2 Stiff Stilbene as a Molecular Force Probe -- 12.2.1 Introduction to Polymer Mechanochemistry -- 12.2.2 The Importance of Model Studies in Polymer Mechanochemistry -- 12.2.3 Stiff Stilbene Is an Effective Molecular Force Probe -- 12.2.4 How Intrinsic Mechanochemical Reactivity Is Measured with Stiff Stilbene -- 12.2.5 How Stiff Stilbene Advanced Our Understanding of Mechanochemistry -- 12.2.5.1 The Restoring Force of a Stretched Monomer Predicts Its Reactivity Independent of How the Force Is Generated -- 12.2.5.2 Experimental Validation of a Simple Model of Mechanochemical Kinetics Over Complex Energy Landscapes -- 12.2.5.3 The Diversity of Force-Reactivity Relationships -- 12.3 Stilbenes in Fundamental Studies of Energy Transduction by Molecular Motors -- 12.3.1 Introduction to Molecular Machines -- 12.3.2 Minimalist Design of a Molecular Rotor Realized Using Stilbenes -- 12.4 Summary -- References -- Chapter 13 Indigoid Photoswitches -- 13.1 Indigo -- 13.2 Thioindigo -- 13.3 Hemiindigo -- 13.4 Hemithioindigo -- 13.5 Iminothioindoxyls -- 13.6 Oxindoles and Isoindolinones -- References -- Chapter 14 Donor-Acceptor Stenhouse Adducts.

14.1 Introduction -- 14.2 DASA Synthesis -- 14.2.1 Molecular Photoswitch -- 14.2.2 Photoswitches in Macromolecules -- 14.3 Photoswitching Properties -- 14.3.1 Mechanism -- 14.3.2 The Absorption Properties -- 14.3.3 Dark Equilibria -- 14.3.4 Cyclization Efficiency Under Illumination -- 14.3.5 Electronic Effects -- 14.3.6 Steric Effects -- 14.3.7 Solvent Effects -- 14.3.8 Concentration Effects -- 14.3.9 Cyclization Under Exclusion of Light -- 14.3.10 Role of Water and Substituents on Cyclization and Ring Opening -- 14.4 Illustrative Applications -- 14.4.1 Polarity Change -- 14.4.2 Wavelength Selectivity -- 14.4.3 Sensing -- 14.4.4 Photothermal -- 14.5 Conclusion -- References -- Chapter 15 Imines as Threefold Functional Devices: Motional, Photochemical, Constitutional -- 15.1 Introduction -- 15.2 Imine Photoswitches -- 15.2.1 Electronic Spectra and Photochemical E/Z-Isomerization of Imines -- 15.2.2 Thermal E/Z-Isomerization of Imines -- 15.2.3 Imines as Photoswitches -- 15.2.4 Imines as Light-Driven Molecular Motors -- 15.3 Acylhydrazone and Hydrazone Photoswitches -- 15.3.1 The Triple Dynamics of Imine-Based Photoswitches -- 15.3.2 The Consequences of Pyridyl-Hydrazones Shape Switching -- 15.3.2.1 Photo-Responsive Receptor -- 15.3.2.2 Switchable Catalysis -- 15.3.2.3 Control of Supramolecular Polymerization -- 15.3.2.4 The Dynamics of Molecular Movements -- 15.3.2.5 Adaptation -- 15.3.3 Constitutional Dynamic Networks -- 15.3.3.1 Photoswitching of Constitutional Dynamic Networks -- 15.3.3.2 Photoswitching in Dynamic Covalent Chemistry: The Photodynamic Covalent Bond -- 15.4 Conclusion -- References -- Chapter 16 Norbornadiene/Quadricyclane (NBD/QC) and Conversion of Solar Energy -- 16.1 Introduction -- 16.2 Synthesis -- 16.2.1 Norbornadiene (NBD) -- 16.2.2 Quadricyclane (QC).

16.3 Molecular Engineering of the Norbornadiene/Quadricyclane Photoswitch Toward MOST Application.