title: Photochromic switching of excited-state intramolecular proton-transfer (ESIPT) fluorescence: a unique route to high-contrast memory switching and nondestructive readout.
abstract: Aiming at the high-contrast photochromic switching of fluorescence emission and its perfect nondestructive readout, a polymer film highly loaded with a specific photochromic compound, 1,2-bis(2'-methyl-5'-phenyl-3'-thienyl)perfluorocyclopentene (BP-BTE), and an excited-state intramolecular proton-transfer (ESIPT)-active compound, 2,5-bis(5'-tert-butyl-benzooxazol-2'-yl)hydroquinone (DHBO), was employed in this work. The special class of photochrome, BP-BTE, has negligible absorbance at 415 nm both in the open form and in the 365 nm photostationary state (PSS), and the ESIPT fluorophore, DHBO, emits large Stokes' shifted (175 nm; lambda(max)(abs) = 415 nm, lambda(max)(em) = 590 nm) and enhanced fluorescence (Phi(F)(powder) = 10%, Phi(F)(soln) = 2%). Bistability, high-contrast switching (on/off fluorescence switching ratio >290), nondestructive readout (over 125000 shots), and erasability were all together accomplished in this novel recording medium.
authors.affiliation: School of Materials Science and Engineering ENG445, Seoul National University, San 56-1, Shillim-dong, Kwanak-ku, Seoul 151-744, Korea.
authors.forename: Seon-Jeong
authors.initials: SJ
authors.lastname: Lim
authors.forename: Jangwon
authors.initials: J
authors.lastname: Seo
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Park