Orhan E. | Gundogdu L. | Kose M. | Yokoyama Y.

Article | 2016 | Journal of Photochemistry and Photobiology A: Chemistry314 , pp.164 - 170

Six novel photochromic bisarylpyridazinones containing 2,5-dimethylthiophene or 5-methyl-2-phenylthiazole unit were synthesized, and their photochromic and fluorescence properties were investigated. The bisarylpyridazinones underwent reversible color change upon irradiation with UV or visible light. The effect of solvents on the absorption spectra of the bisarylpyridazinones was investigated. The closed-ring forms of bisarylpyridazinones displayed negative solvatochromism which was attributed to the high dipolar characters of the molecule. The open-ring forms of bisarylpyridazinones showed fluorescence at 400-480 nm upon excitation . . .at 302 nm, and the intensities of emission bands gradually decreased during the ring-closing photoreactions. Among the synthesized bisarylpyridazinones, 4,5-bis(5-methyl-2-phenylthiazol-4-yl)-2-methyl(or 2-phenyl) pyridazin-3(2H)-ones (5O and 6O) displayed rather large absorption and emission spectral change, higher quantum efficiency during the photoreaction compared to others. A high conversion ratio (94%) to the closed form was observed for 5O. © 2015 Elsevier B.V. All rights reserved Daha fazlası Daha az

Gundogdu L. | Kose M. | Takeuchi S. | Yokoyama Y. | Orhan E.

Article | 2018 | Journal of Luminescence203 , pp.568 - 575

Two new bithiazole-containing diarylethenes, 1-[5-methyl-2-(5-methyl-2-thiazolyl)-4-thiazolyl]-2,5-dimethyl-3-thienyl-3,3,4,4,5,5-hexafluorocyclopentene and 1-[5-methyl-2-(5-methyl-2-thiazolyl)-4-thiazolyl]-2-methyl-3-benzothienyl-3,3,4,4,5,5-hexafluorocyclopentene were synthesized and their photochromic and fluorescent properties have been investigated. They exhibited thermally irreversible photochromism and fluorescent switching in toluene. The effects of complexation of these two compounds with various metal cations such as Na+, Ag+, Hg+, Co2+, Ni2+, Cu2+, Ba2+, Zn2+, Cr3+, Pb2+, Cd2+, Sn2+, Al3+, Fe3+ on photochromic and fluores . . .cent properties were also studied. Metal cations caused small effects on the absorption bands of their ring closed forms. However, fluorescence intensities of both compounds were strongly suppressed by Ni2+, Cu2+ and Fe3+. © 2018 Elsevier B.V Daha fazlası Daha az