Photochromic switching

As for the relevant application, recently, a specific photochromic compound, 1,2-bis(2 -methyl-5 -phenyl-3 -thienyl)perfluorocyclopentene (BP-BTE), and the analogs of HBO, 2,5-bis(5,-0 rt-butyl-benzooxazol-2 -yl)hydroquinone (DHBO), were employed in the high-contrast, reversible, photochromic switching of fluorescence emission and its perfect nondestructive readout (Fig. 14). Due to the large... 

Stokes-shifted tautomer emission and high quantum yield in solid state (10%), DHBO was successfully used as an energy transfer donor in the photochromic switching system [88]. 

Lim SJ, Seo J, Park SY (2006) Photochromic switching of excited-state intramolecular proton-transfer (ESIPT) fluorescence a unique route to high-contrast memory switching and nondestructive readout. J Am Chem Soc 128 14542-14547... 

Belser, P., De Cola, L., Hard, F., et al., Photochromic switches incorporated in bridging ligands A new tool to modulate energy-transfer processes. Advanced Functional Materials 2006, 16, 195-208. 

Attachment of DHA 26a to cellulose, as a biopolymer representative, provides another way to test the feasibility of multifold photochromic switching within a... 

Recent advances in organic photochromic storage materials, and photochromic switching, have also been described. 

FIGURE 6.3 Photochromic switching of spiropyran attached to a Wang resin. 

The Dithienylethene System and Related Compounds. The area of diaryl-ethenes has been the subjeet of a review.Calculations have been carried out dealing with the photochromism of such compounds.A description of the preparation of diarylethene nanoparticles has been published, and a decrease in photocyclization was attributed to aggregation. Some novel photochromic diarylethenes have been synthesized. The photochemistry exhibited by these compounds suggests that they could be of use as optical switches.Tian and Yang have reviewed the area of diarylethene photochromic switches. 1,2-Bis(2-methylbenzo[b]thiophen-3-yl)hexafluorocyclopentene is at the basis of a new photochromic liquid crystal system. Yokoyama and his co-workers have patented details for such photochromic materials." ... 

Several reviews have been published within the year which are of general relevance to the photoreactions of aromatic compounds. The subjects of these reviews include photochemistry in ionic liquids and in isotropic and anisotropic media, organic synthesis utilizing photoinduced electron-transfer reactions," heteroatom-directed photoarylation processes, photochromism, and photochemical molecular devices. Reviews more directly pertinent to the sections in the present chapter include those of the photoisomerization of five-membered heteroaromatic azoles, the photocycloaddition of benzene derivatives to alkenes, Diels-Alder additions of anthracenes, advances in the synthesis of polycyclic aromatic compounds, diarylethene-based photochromic switches, the photo-Fries rearrangement, and the application of Diels-Alder trapping of photogenerated o-xylenols to the synthesis of novel compounds. " A number of chapters in the two recently published handbooks of photochemistry and photobiology and in the revised edition of the text on photochromism are also pertinent to the current subject matter. 

Electron and energy transfer modulation with photochromic switches (dithienylethenes and spiro[chromene-2,2 -indolines]) 05CSR327. 

H. Tian, S. Yang, Recent progresses on diarylethene based photochromic switches. Chem. Soc. Rev. 33, 85-97 (2004)... 

Storage and processing of information using molecules The allphotonic approach with simple and multi-photochromic switches 13IJC236. 

Optically induced cis-trans isomerization is a key structural dynamic element for many types of photochromic switches as stilbenes and azobenzene derivatives and for photosensor proteins as bacteriorhodopsin, rhodopsin, and photoactive yellow protein. 

F. M. Raymo, M. Tomasulo, Optical processing with photochromic switches, Chem. Eiir. J., 12, 3186-3193 (2006). 

Access to the third dimension via aluminosilicate frameworks, which comprise regular structured nanopores, has been suggested. These hollow networks house conducting polymer chains as wires and semiconductor dots to give a zeolite memory, with potentially 10 cross-points as storage elements, due to their bistable behavior, per cubic centimeter photochromic switches have also been incorporated into silica monoliths. 

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