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Photochromism of diarylethene molecules and crystals.

Irie M - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2010)

Bottom Line: The thermal irreversibility is an indispensable property for the application of photochromic molecules to optical memories and switches.We have developed a new class of photochromic molecules named "diarylethenes", which show the thermally irreversible photochromic reactivity.The well designed diarylethene derivatives provide outstanding photochromic performance: both isomers are thermally stable for more than 470,000 years, photoinduced coloration/decoloration can be repeated more than 10(5) cycles, the quantum yield of cyclization reaction is close to 1 (100%), and the response times of both coloration and decoloration are less than 10 ps.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Research Center for Smart Molecules, Rikkyo University, Tokyo, Japan.

ABSTRACT
Photochromism is defined as a reversible transformation of a chemical species between two isomers upon photoirradiation. Although vast numbers of photochromic molecules have been so far reported, photochromic molecules which exhibit thermally irreversible photochromic reactivity are limited to a few examples. The thermal irreversibility is an indispensable property for the application of photochromic molecules to optical memories and switches. We have developed a new class of photochromic molecules named "diarylethenes", which show the thermally irreversible photochromic reactivity. The well designed diarylethene derivatives provide outstanding photochromic performance: both isomers are thermally stable for more than 470,000 years, photoinduced coloration/decoloration can be repeated more than 10(5) cycles, the quantum yield of cyclization reaction is close to 1 (100%), and the response times of both coloration and decoloration are less than 10 ps. This review describes theoretical background of the photochromic reactions, color changes of the derivatives in solution as well as in the single crystalline phase, and application of the crystals to light-driven actuators.

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Typical examples of photochromic molecules.
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fig01: Typical examples of photochromic molecules.

Mentions: Photochromic molecules are characterized by their reversible color changes upon photoirradiation.1–3) Typical examples of photochromic molecules, which show such color changes, are shown in Fig. 1. The upper two molecules, azobenzene and spiropyran, change the color from colorless to orange and blue, respectively. These traditional molecules are classified into T-type (thermally reversible) photochromic ones. The photogenerated right-side isomers are thermally unstable and the colors slowly disappear in the dark. On the other hand, recently invented lower two molecules, furylfulgide and diarylethene, both of which change the color from colorless to red, are classified into P-type (thermally irreversible, but photochemically reversible) photochromic ones. In these P-type photochromic molecules, photogenerated right-side isomers are thermally stable and scarcely return to the left-side isomers in the dark at room temperature. The thermally irreversible property is indispensable for the application to optical memories and switches. The thermal irreversibility of diarylethene derivatives will be discussed in detail later.


Photochromism of diarylethene molecules and crystals.

Irie M - Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci. (2010)

Typical examples of photochromic molecules.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3108296&req=5

fig01: Typical examples of photochromic molecules.
Mentions: Photochromic molecules are characterized by their reversible color changes upon photoirradiation.1–3) Typical examples of photochromic molecules, which show such color changes, are shown in Fig. 1. The upper two molecules, azobenzene and spiropyran, change the color from colorless to orange and blue, respectively. These traditional molecules are classified into T-type (thermally reversible) photochromic ones. The photogenerated right-side isomers are thermally unstable and the colors slowly disappear in the dark. On the other hand, recently invented lower two molecules, furylfulgide and diarylethene, both of which change the color from colorless to red, are classified into P-type (thermally irreversible, but photochemically reversible) photochromic ones. In these P-type photochromic molecules, photogenerated right-side isomers are thermally stable and scarcely return to the left-side isomers in the dark at room temperature. The thermally irreversible property is indispensable for the application to optical memories and switches. The thermal irreversibility of diarylethene derivatives will be discussed in detail later.

Bottom Line: The thermal irreversibility is an indispensable property for the application of photochromic molecules to optical memories and switches.We have developed a new class of photochromic molecules named "diarylethenes", which show the thermally irreversible photochromic reactivity.The well designed diarylethene derivatives provide outstanding photochromic performance: both isomers are thermally stable for more than 470,000 years, photoinduced coloration/decoloration can be repeated more than 10(5) cycles, the quantum yield of cyclization reaction is close to 1 (100%), and the response times of both coloration and decoloration are less than 10 ps.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Research Center for Smart Molecules, Rikkyo University, Tokyo, Japan.

ABSTRACT
Photochromism is defined as a reversible transformation of a chemical species between two isomers upon photoirradiation. Although vast numbers of photochromic molecules have been so far reported, photochromic molecules which exhibit thermally irreversible photochromic reactivity are limited to a few examples. The thermal irreversibility is an indispensable property for the application of photochromic molecules to optical memories and switches. We have developed a new class of photochromic molecules named "diarylethenes", which show the thermally irreversible photochromic reactivity. The well designed diarylethene derivatives provide outstanding photochromic performance: both isomers are thermally stable for more than 470,000 years, photoinduced coloration/decoloration can be repeated more than 10(5) cycles, the quantum yield of cyclization reaction is close to 1 (100%), and the response times of both coloration and decoloration are less than 10 ps. This review describes theoretical background of the photochromic reactions, color changes of the derivatives in solution as well as in the single crystalline phase, and application of the crystals to light-driven actuators.

Show MeSH
Related in: MedlinePlus