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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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Reversible bending a crystal-rod of 24a upon irradiation with UV and visible light.
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fig13: Reversible bending a crystal-rod of 24a upon irradiation with UV and visible light.

Mentions: A rod-like crystal was also prepared from 24a by sublimation. The rod-like crystal mounted at one end on a glass surface bent upon irradiation with UV light. The rod bent towards the direction of the incident light. This effect is due to the gradient in the extent of photoisomerization caused by the high absorbance of the crystal, so that the shrinkage of the irradiated part of the crystal causes bending just as in a bimetal. The bent rod-like crystal became straight upon irradiation with visible light. Such reversible bending could be repeated over 80 cycles, as shown in Fig. 13.


Photochromism of diarylethene molecules and crystals.

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

Reversible bending a crystal-rod of 24a upon irradiation with UV and visible light.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig13: Reversible bending a crystal-rod of 24a upon irradiation with UV and visible light.
Mentions: A rod-like crystal was also prepared from 24a by sublimation. The rod-like crystal mounted at one end on a glass surface bent upon irradiation with UV light. The rod bent towards the direction of the incident light. This effect is due to the gradient in the extent of photoisomerization caused by the high absorbance of the crystal, so that the shrinkage of the irradiated part of the crystal causes bending just as in a bimetal. The bent rod-like crystal became straight upon irradiation with visible light. Such reversible bending could be repeated over 80 cycles, as shown in Fig. 13.

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