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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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Thermal stability of photogenerated closed-ring isomers of diarylethene derivatives having various types of side groups.
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fig04: Thermal stability of photogenerated closed-ring isomers of diarylethene derivatives having various types of side groups.

Mentions: The theoretical prediction was confirmed by the synthesis of diarylethene derivatives with various types of side groups, as shown in Fig. 4.16) When the side groups are furan, thiophene, benzothiophene, benzofuran, thiazole, oxazole rings, which have low aromatic stabilization energy, the closed-ring isomers are thermally stable and hardly return to the open-ring isomers. On the other hands, photogenerated close-ring isomers of diarylethenes with phenyl or indole rings, which have rather high aromatic stabilization energy, are thermally unstable. They return to the open-ring isomers even in the dark. The basic principle that diarylethene derivatives having side groups with low aromatic stabilization energy exhibit thermal irreversibility has been established based on the theoretical consideration as well as the supporting experimental results.


Photochromism of diarylethene molecules and crystals.

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

Thermal stability of photogenerated closed-ring isomers of diarylethene derivatives having various types of side groups.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig04: Thermal stability of photogenerated closed-ring isomers of diarylethene derivatives having various types of side groups.
Mentions: The theoretical prediction was confirmed by the synthesis of diarylethene derivatives with various types of side groups, as shown in Fig. 4.16) When the side groups are furan, thiophene, benzothiophene, benzofuran, thiazole, oxazole rings, which have low aromatic stabilization energy, the closed-ring isomers are thermally stable and hardly return to the open-ring isomers. On the other hands, photogenerated close-ring isomers of diarylethenes with phenyl or indole rings, which have rather high aromatic stabilization energy, are thermally unstable. They return to the open-ring isomers even in the dark. The basic principle that diarylethene derivatives having side groups with low aromatic stabilization energy exhibit thermal irreversibility has been established based on the theoretical consideration as well as the supporting experimental results.

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