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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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Photoinduced color and shape changes of single crystals of (a) 23a and (b) 24a upon irradiation with UV and visible light.
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fig12: Photoinduced color and shape changes of single crystals of (a) 23a and (b) 24a upon irradiation with UV and visible light.

Mentions: Figure 12 shows the color and shape changes of 1,2-bis(2-ethyl-5-phenyl-3-thienyl)perfluorocyclopentene (23a) and 1,2-bis(5-methyl-2-phenyl-4-thiazolyl)perfluorocyclopentene (24a) crystals upon irradiation with UV (365 nm) and visible (>500 nm) light. The color of the two crystals turned blue and violet, respectively. The colors are stable in the dark, but disappeared on irradiation with visible light. UV irradiation changed the corner angle of the single crystal 23 from 88° and 92° to 82° and 98° and hence the shape from a square to a lozenge. On the other hand, the crystal 24 exhibited reversible contraction/expansion in length as much as 5–7% upon alternate irradiation with UV and visible light.


Photochromism of diarylethene molecules and crystals.

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

Photoinduced color and shape changes of single crystals of (a) 23a and (b) 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

fig12: Photoinduced color and shape changes of single crystals of (a) 23a and (b) 24a upon irradiation with UV and visible light.
Mentions: Figure 12 shows the color and shape changes of 1,2-bis(2-ethyl-5-phenyl-3-thienyl)perfluorocyclopentene (23a) and 1,2-bis(5-methyl-2-phenyl-4-thiazolyl)perfluorocyclopentene (24a) crystals upon irradiation with UV (365 nm) and visible (>500 nm) light. The color of the two crystals turned blue and violet, respectively. The colors are stable in the dark, but disappeared on irradiation with visible light. UV irradiation changed the corner angle of the single crystal 23 from 88° and 92° to 82° and 98° and hence the shape from a square to a lozenge. On the other hand, the crystal 24 exhibited reversible contraction/expansion in length as much as 5–7% upon alternate irradiation with UV and visible light.

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