Photochromic Compounds

Photochromism is the phenomena that of reversible transformation between two forms that have different absorption spectra by photo-irradiation. The history of photochromism dates back to the era of the Alexander the Great. Inspired by Fischer and co-workers who first reported photochromism in spiropyran analogues in 1952, intense studies on photochromic compounds have continued up to the present. The mechanism for photochromism of spiropyran analogues is shown below.

Today, research for the application of photochromism is being achieved in a variety of fields including light modulation materials, optical recording materials, optical switches, and photochromic ink. Some of them are being put into practical use. Furthermore, an energetic attempt to introduce photochromic compounds into functional materials for photochemical control is being studied. Especially, diarylethenes 1 and 2 developed by Irie and co-workers are stable at high temperature and have been shown high repeated durability. In addition, various functional molecules can easily be introduced to the aromatic ring of 1 and 2. The solution of 1 changes to red upon irradiation of UV light, but rapidly converts back to olorless by visible light. In this reversible reaction, 1 has been shown a repeated durability over 10,000 times. The crystal of 2 changes to blue upon irradiation of UV light, and returns to colorless by visible light. These changes are rapidly finished within ten pico second. Moreover, the photocyclization quantum yields is limitlessly near to one. Therefore 2 shows extremely effective photochromic reaction. 1 and 2 are ideal optical device material and are expected as one of the material supporting the photonics age in the 21th century.

Diarylethenes

Spiropyrans

Spiroperimidines

Viologens (Related Compounds)

Others

Diarylethenes

B2629 B2629 B2287 B2287 B1534 B1534
B1535 B1535 B1536 B1536
B2629 1,2-Bis(2,4-dimethyl-5-phenyl-3-thienyl)-3,3,4,4,5,5-hexafluoro-1-cyclopentene
B2287 1,2-Bis[2-methylbenzo[b]thiophen-3-yl]-3,3,4,4,5,5-hexafluoro-1-cyclopentene
B1534 2,3-Bis(2,4,5-trimethyl-3-thienyl)maleic Anhydride
B1535 2,3-Bis(2,4,5-trimethyl-3-thienyl)maleimide
B1536 cis-1,2-Dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene
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Spiropyrans

H1042 H1042 T0344 T0344 T0370 T0370
T0416 T0416 T0423 T0423 T1259 T1259
T0366 T0366
H1042 1-(2-Hydroxyethyl)-3,3-dimethylindolino-6'-nitrobenzopyrylospiran
T0344 1,3,3-Trimethylindolinobenzopyrylospiran [Photochromic Compound]
T0370 1,3,3-Trimethylindolino-6'-bromobenzopyrylospiran [Photochromic Compound]
T0416 1,3,3-Trimethylindolino-8'-methoxybenzopyrylospiran [Photochromic Compound]
T0423 1,3,3-Trimethylindolino-beta-naphthopyrylospiran [Photochromic Compound]
T1259 1,3,3-Trimethylindolinonaphthospirooxazine [Photochromic Compound]
T0366 1,3,3-Trimethylindolino-6'-nitrobenzopyrylospiran [Photochromic Compound]
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Spiroperimidines

D3618 D3618 D3619 D3619
D3618 2,3-Dihydro-2-spiro-4'-[8'-aminonaphthalen-1'(4'H)-one]perimidine (contains o-form)
D3619 2,3-Dihydro-2-spiro-7'-[8'-imino-7',8'-dihydronaphthalen-1'-amine]perimidine
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Viologens (Related Compounds)

B0469 B0469 B1518 B1518 D2137 D2137
D1593 D1593 D1854 D1854 D2165 D2165
B0469 4,4'-Bipyridyl
B1518 1,1'-Bis(2,4-dinitrophenyl)-4,4'-bipyridinium Dichloride
D2137 1,1'-Dibenzyl-4,4'-bipyridinium Dichloride Hydrate
D1593 1,1'-Diheptyl-4,4'-bipyridinium Dibromide [for Electrochromic Material]
D1854 1,1'-Di-n-octyl-4,4'-bipyridinium Dibromide
D2165 1,1'-Diphenyl-4,4'-bipyridinium Dichloride
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Others

A0565 A0565 D3197 D3197 N0346 N0346
T1489 T1489
A0565 Azobenzene
D3197 3,3-Diphenyl-3H-naphtho[2,1-b]pyran
N0346 2,5-Norbornadiene (stabilized with BHT)
T1489 Thioindigo
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Literature

E. Fischer, Y. Hirshberg, J. Chem. Soc., 1952, 4522 [DOI].
G. H. Brown, “Techniques of Chemistry, Vol.III,Photochromism”, Wiley-Interscience (1971).
S. Irie, T. Yamaguchi, H. Nakazumi, S. Kobatake, M. Irie, Bull. Chem. Soc. Jpn., 1999, 72, 1139 [DOI].
S. Kobata, M. Irie, Kagaku (Chemistry), 2001, 56(11), 19.
M. Irie, Chem. Rev., 2000, 100, 1685 [DOI].
K. Matsuda, M. Irie, TCIMAIL, 2003, number 120, 2 [DOI].

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