Chapter 7
Photochromism
Seiya Kobatake
Abstract Photochromic compounds can be divided into two types, T- and P-types.
T-type photochromic compounds include azobenzene, spiropyran, hexaarylbiimidazole, spirooxazine, naphthopyran, and the donor-acceptor Stenhouse adduct,
as introduced here. In P-type photochromic compounds, there are furylfulgide
and diarylethene. Diarylethene derivatives have the most excellent photochromic
compounds, such as thermal stability of both isomers, high fatigue-resistance, high
response, high sensitivity, high coloration quantum yield, and high reactivity even in
the crystalline phase. In this chapter, the photochromic properties of these compounds
have been focused.
Keywords Photochromism · Photoswitching · T-type · P-type · Diarylethene ·
Photoactuator
7.1 Introduction
Photochromism is a phenomenon in which the color changes reversibly by light, and
a compound exhibiting such a phenomenon is called a photochromic compound. The
history of photochromism is old and the first report of academic research is reaction
with oxygen by irradiation to tetracene solution in air, reported by Fritzsche (1867).
The produced endoperoxide desorbs oxygen at room temperature to return to the
original compound. Regarding the history of photochromism, it is written in detail in
some literature (Crano and Guglielmetti 1999; Dürr and Bouas-Laurent 2003; Tian
and Zhang 2016). The photochromic compounds exhibit changes in various chemical and physical properties such as absorption spectra, refractive indices, dielectric constants, oxidation-reduction potentials, and geometrical structures by photoirradiation. The photoinduced rapid properties changes lead to their use in various
optoelectronic devices, such as optical memories, photoswitching, image recording,
photomechanical devices, and so on.
S. Kobatake (B)
Graduate School of Engineering, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka
558-8585, Japan
e-mail: kobatake@a-chem.eng.osaka-cu.ac.jp
© Springer Nature Singapore Pte Ltd. 2021
Y. Ooyama and S. Yagi (eds.), Progress in the Science of Functional Dyes,
https://doi.org/10.1007/978-981-33-4392-4_7
263
Photochromism
Seiya Kobatake
Abstract Photochromic compounds can be divided into two types, T- and P-types.
T-type photochromic compounds include azobenzene, spiropyran, hexaarylbiimidazole, spirooxazine, naphthopyran, and the donor-acceptor Stenhouse adduct,
as introduced here. In P-type photochromic compounds, there are furylfulgide
and diarylethene. Diarylethene derivatives have the most excellent photochromic
compounds, such as thermal stability of both isomers, high fatigue-resistance, high
response, high sensitivity, high coloration quantum yield, and high reactivity even in
the crystalline phase. In this chapter, the photochromic properties of these compounds
have been focused.
Keywords Photochromism · Photoswitching · T-type · P-type · Diarylethene ·
Photoactuator
7.1 Introduction
Photochromism is a phenomenon in which the color changes reversibly by light, and
a compound exhibiting such a phenomenon is called a photochromic compound. The
history of photochromism is old and the first report of academic research is reaction
with oxygen by irradiation to tetracene solution in air, reported by Fritzsche (1867).
The produced endoperoxide desorbs oxygen at room temperature to return to the
original compound. Regarding the history of photochromism, it is written in detail in
some literature (Crano and Guglielmetti 1999; Dürr and Bouas-Laurent 2003; Tian
and Zhang 2016). The photochromic compounds exhibit changes in various chemical and physical properties such as absorption spectra, refractive indices, dielectric constants, oxidation-reduction potentials, and geometrical structures by photoirradiation. The photoinduced rapid properties changes lead to their use in various
optoelectronic devices, such as optical memories, photoswitching, image recording,
photomechanical devices, and so on.
S. Kobatake (B)
Graduate School of Engineering, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka
558-8585, Japan
e-mail: kobatake@a-chem.eng.osaka-cu.ac.jp
© Springer Nature Singapore Pte Ltd. 2021
Y. Ooyama and S. Yagi (eds.), Progress in the Science of Functional Dyes,
https://doi.org/10.1007/978-981-33-4392-4_7
263