Diarylethene Molecular Photoswitches

Masahiro Irie is an emeritus professor of Kyushu University. He received his B.S. and M.S. from Kyoto University and his Ph.D. in radiation chemistry from Osaka University. In 1968 he joined the Faculty of Engineering, Hokkaido University, as a research associate and started his research in photochemistry. He was the faculty members of at Osaka University, Kyushu University and Rikkyo University. He has been conducting research on molecular photoswitch systems for more than 40 years. In the middle of the 1980s he discovered thermally irreversible and fatigue resistant photochromic diarylethenes. Prof. Irie has authored over 500 scientific publications and has received numerous scientific awards, including Porter Medal (European Photochemistry Association, The Inter-American Photochemistry Society and Asian and oseanian Photochemsitry association), Theodor-Foerster-Preis (GDCh and Deutsche Bunsen-Gesellschaft, Germany) and The Chemical Society of Japan Award.

1. Introduction
1.1 General Introduction
1.2 Discovery of Diarylethene Molecular Photoswitches
2. Reaction Mechanism
2.1 Basic Concepts
2.2 Theoretical Study
2.3 Reaction Dynamics
2.3.1 Cyclization Reaction
2.3.2 Cycloreversion Reaction
3. Photoswitching Performance
3.1 Quantum Yield
3.1.1 Photocyclization Quantum Yield
3.1.2 Solvent Effect on Cyclization Quantum Yield
3.1.3 Photocycloreversion Quantum Yield
3.2 Thermal Stability
3.3 Fatigue Resistance
3.4 Fluorescence Property
3.4.1 Turn-off Mode Photoswitching
3.4.2 Turn-on Mode Photoswitching
3.5 Chiral Property
4. Photoswitchable Crystals
4.1 Dichroism
4.2 X-Ray Crystallographic Analysis
4.3 Quantum Yield
4.4 Multicoloured Systems and Nano-layered Periodic Structures
4.5 Fluorescent Crystals
4.6 Photomechanical Response
4.6.1 Surface Morphology Change
4.6.2 Reversible Shape Change
4.6.3 Bending Response of Mixed Crystals
5. Memory
5.1 Single-Molecule Memory
5.2 Near-Field Optical Memory
5.3 Three-Dimensional Optical Memory
5.4 Readout using Infrared (IR) Absorption, Raman Scattering and Refractive Index Changes
6. Switches
6.1 Single-Molecule Conductance Photoswitch
6.2 Optical Switch based on Refractive Index Change
6.3 Magnetism
7. Surface Properties
7.1 Surface Wettability
7.2 Selective Metal Deposition
7.3 Subwavelength Nanopatterning
8. Polymers and Liquid Crystals
8.1 Polymers
8.2 Liquid Crystals
9. Applications
9.1 Organic Field-Effect Transistors (OFETs)
9.2 Metal Organic Frameworks (MOFs)
9.3 Super-resolution Fluorescence Microscopy
9.3.1 Control of Cycloreversion Quantum Yield
9.3.2 Fatigue Resistance
9.3.3 Photoswitching with Single-Wavelength Visible Light
9.3.4 Super-resolution Bioimaging
9.4 Chemical Reactivity Control
9.5 Biological Activity
9.6 Colour Dosimeters
10. Appendix