Xanthene

About: Xanthene is a research topic. Over the lifetime, 2132 publications have been published within this topic receiving 34803 citations. The topic is also known as: Xanthene & dibenzo[a,e]pyran.

Synthesis and photochemical behavior of xanthene dye-peroxybenzoate initiators

Abstract: A series of xanthene dyes bearing a tert-butyl peroxybenzoate moiety was synthesized. The fluorescence and phosphorescence spectra were measured to determine the photoproperties of xanthene dye peresters. The transient phenomena were also examined by nanosecond laser flash photolysis in organic solvents at room temperature. Furthermore, the photodecomposition behavior of these compounds was followed by UV-VIS absorption and the final decomposition products were distinguished by comparing IR spectra before and after the irradiation with an Ar + laser at 514.5 nm. To prove their application to information recording materials, the sensitivities for the visible light initiating system are also reported.

Xanthene-dyed dichromated colloid systems for real-time hologram recording

Abstract: Holographic optical elements (HOEs) play a key role in the optical processing and optical computing fields as well as in non-destructive holographic testing studies. The fabrication of such linear and nonlinear HEOs requires high quality recording films; in the search of such a recording material, we studied photocrosslinking colloid systems like dichromated polyvinyl alcohol films (DC-PVAL). Those films gave holograms having a maximum diffraction efficiency value (MDE) of 18% at 488 nm; at 442 nm, we obtained MDE values between 20% and 55%. When adding a xanthene dye, the MDE value may be increased. In the present communication we introduce many new results on hologram recordings with another kind of xanthene dye dichromated colloid film at 442 nm. Also the knowledge of characteristic properties of such xanthene dye DC-colloids films permits us to focus on `How they are usable in engineering applications.'© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Studies on Triplet-Singlet Energy Transfer in the System Benzophenone—Xanthene Dye

Abstract: The transfer of electronic energy from triplet donors benzophenones to different xanthene dyes as acceptors is studied in rigid glassy solution. The acceptors are excited to their fluorescing states and the delayed emission of both donors and acceptors is measured with a calibrated phosphoroscope. Increasing halogenisation of the dyes enhances the rate of this “forbidden” triplet-singlet transfer.

Photogalvanic cells based on the photoreduction of xanthene dyes using riboflavin as a sensitizer in aqueous/micellar medium

Abstract: The photochemical reduction of fluorescein, eosin (Y) and rosebengal by disodium salt of EOTA using riboflavin (Bz) as a sensitizer has been studied in aqueous, neutral (triton X-lOO) and cationic (CTPB) micellar media. The two micelles (i.e. neutral and cationic) are found to catalyse the electron transfer from reduced riboflavin to the dye in the forward photoreaction. Oxidation of semi-reduced dye radical (DH) at the anode (Pt electrode) in a two-compartment photogalvanic (PG) cell which contains riboflavin, NazEOTA and dye (0) in the photoanode compartment and 1.0 M HCI04 in the dark cathode compartment generates noticeable photocurrents. Remarkable increase in photocurrent is noticed in the micellar medium compared to that in the aqueous medium. The stability of the cell also increases in micellar medium.