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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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Photochromic reactions of fused trimer 19 and the color changes upon irradiation with the appropriate wavelength of light.
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fig07: Photochromic reactions of fused trimer 19 and the color changes upon irradiation with the appropriate wavelength of light.

Mentions: In normal photochromic systems they interconvert between only two states: colorless and colored. If multi-color photochromic molecules are prepared, they are useful for multifrequency optical memories and displays. We took an approach to incorporate three photochromic units in one molecule.29) The advantage of the one-molecule system over mixture systems is high image resolution, constant color balance in a large area and possible application to multifrequency single-molecule memory. Figure 7a shows the fused trimer (19a) along with anticipated photochromic reactions. The fused trimer has three dithienylethene moieties, bis(2-thienyl)ethene, (2-thienyl)(3-thienyl)ethene and bis(3-thienyl)ethene, with two thiophene rings in common. Upon irradiation with UV (313 nm) light the hexane solution containing 19a turned black. When UV (313 nm) and blue (460 nm) light was simultaneously irradiated, the solution turned sky blue. When the solution was irradiated with UV (313 nm) and red (633 nm) light, the solution turned to red. The solution turned to yellow when the solution was irradiated UV (313 nm) and yellow (578 nm) light. The solution containing 19a can develop blue, red, and yellow colors upon irradiation with appropriate wavelength of light, suggesting that all of the three diarylethene moieties can cyclize upon irradiation, as shown in Figure 7b.


Photochromism of diarylethene molecules and crystals.

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

Photochromic reactions of fused trimer 19 and the color changes upon irradiation with the appropriate wavelength of light.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig07: Photochromic reactions of fused trimer 19 and the color changes upon irradiation with the appropriate wavelength of light.
Mentions: In normal photochromic systems they interconvert between only two states: colorless and colored. If multi-color photochromic molecules are prepared, they are useful for multifrequency optical memories and displays. We took an approach to incorporate three photochromic units in one molecule.29) The advantage of the one-molecule system over mixture systems is high image resolution, constant color balance in a large area and possible application to multifrequency single-molecule memory. Figure 7a shows the fused trimer (19a) along with anticipated photochromic reactions. The fused trimer has three dithienylethene moieties, bis(2-thienyl)ethene, (2-thienyl)(3-thienyl)ethene and bis(3-thienyl)ethene, with two thiophene rings in common. Upon irradiation with UV (313 nm) light the hexane solution containing 19a turned black. When UV (313 nm) and blue (460 nm) light was simultaneously irradiated, the solution turned sky blue. When the solution was irradiated with UV (313 nm) and red (633 nm) light, the solution turned to red. The solution turned to yellow when the solution was irradiated UV (313 nm) and yellow (578 nm) light. The solution containing 19a can develop blue, red, and yellow colors upon irradiation with appropriate wavelength of light, suggesting that all of the three diarylethene moieties can cyclize upon irradiation, as shown in Figure 7b.

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