Orhan, Ersin | Kose, Mahmut | Yazan, Tolga

Article | 2018 | TURKISH JOURNAL OF CHEMISTRY42 ( 4 ) , pp.1086 - 1094

Three new photochromic compounds, 3-(2,5-dimethyl-3-thienyl)-4-(2-phenyl-5-methyl-4-thiazolyl)-l,8-naphthalimide (1-O), 2,3-bis(2-phenyl-5-methyl-4-thiazolyl)-7H-benzimidazo[2,1-a]benzo[de]isoquinolin-7-one (2-O), and 2,5-dimethyl-3-thienyl)-7H-benzimidazo[2,1-a]benzo[de]isoquinolin-7-one (3-O), were synthesized and their photochromic properties were studied. Compound 1-O was synthesized by two consecutive Suzuki coupling reactions using 2,5-dimethylthiophene-3-boronic acid and 5-methyl-2-phenylthiazole-4-boronic acid. Photochromic compounds 2-O and 3-O were prepared by multistep reactions starting with 3-iodo-4-bromo-1,8-naphthalic . . . anhydride and 2,5-dimethylthiophene3-boronic acid or 2-phenyl-5-methylthiazole-4-boronic acid. All photochromic compounds showed a color change from colorless (or light yellow) to blue-green, purple, or orange colors (depending on the nature of the structures) on exposure to UV light at 365 nm in ethyl acetate solutions. The colored solutions can be reversed to the original colorless (or light yellow) solution by exposure to visible light at 530 nm Daha fazlası Daha az

Kose M. | Orhan E. | Suzuki K. | Tutar A. | Ünlü C.S. | Yokoyama Y.

Article | 2013 | Journal of Photochemistry and Photobiology A: Chemistry257 , pp.50 - 53

From 2,3-dibromobenz[f]indenone, four compound: 2,3-bis(5-methyl-2-phenyl- 4-thiazolyl)benz[f]indenone 1O, 2,3-bis(3,5-dimethyl-4-isoxazolyl)benz[f] indenone 2O, 3-(3,5-dimethyl-4-isoxazolyl)-2-(5-methyl-2-phenyl-4-thiazolyl) benz[f]indenone 3O and 2,3-bis(5-methyl-2-phenyl-4-thiazolyl)benz[f]indenol 4O were prepared, and their photochromic properties were investigated. Among them, photochrome 1O (weak photochromic) and its bisthiazolylbenz[f]indenol derivative 4O displayed photochromism. During ring closure photoreaction, photochrome 4O showed high conversion ratio (98.4%) with low diastereomeric excess (38%). © 2013 Elsevier B.V. . . .All rights reserved Daha fazlası Daha az

Orhan E. | Köse M. | Yazan T.

Article | 2018 | Turkish Journal of Chemistry42 ( 4 ) , pp.1086 - 1094

Three new photochromic compounds, 3-(2,5-dimethyl-3-thienyl)-4-(2-phenyl-5-methyl-4-thiazolyl)-1,8-napht-halimide (1-O), 2,3-bis(2-phenyl-5-methyl-4-thiazolyl)-7H-benzimidazo[2,1-a]benzo[de]isoquinolin-7-one (2-O), and 2,5-dimethyl-3-thienyl)-7H-benzimidazo[2,1-a]benzo[de]isoquinolin-7-one (3-O), were synthesized and their photochromic properties were studied. Compound 1-O was synthesized by two consecutive Suzuki coupling reactions using 2,5-dimethylthiophene-3-boronic acid and 5-methyl-2-phenylthiazole-4-boronic acid. Photochromic compounds 2-O and 3-O were prepared by multistep reactions starting with 3-iodo-4-bromo-1,8-naphthali . . .c anhydride and 2,5-dimethylthiophene-3-boronic acid or 2-phenyl-5-methylthiazole-4-boronic acid. All photochromic compounds showed a color change from colorless (or light yellow) to blue-green, purple, or orange colors (depending on the nature of the structures) on exposure to UV light at 365 nm in ethyl acetate solutions. The colored solutions can be reversed to the original colorless (or light yellow) solution by exposure to visible light at 530 nm. © TÜBİTA Daha fazlası Daha az

Kose M. | Şekerci C.Y. | Suzuki K. | Yokoyama Y.

Article | 2011 | Journal of Photochemistry and Photobiology A: Chemistry219 ( 1 ) , pp.58 - 61

2,3-Bis(5-methyl-2-phenyl-4-thiazolyl)-1,4-naphthoquinone 1-O, its monoethylene acetal 2-O and methylated derivatives 3-O and 4-O were synthesized and their photochromic properties were investigated. While bisarylnaphthoquinone 1-O was nonphotochromic, its monoacetal 2-O and methylated derivatives 3-O and 4-O displayed good photochromism. Among them, the isomer 4-O recorded a remarkable diastereomeric excess (98.40%) with high conversion ratio (96.20%) upon UV irradiation. © 2011 Elsevier B.V. All rights reserved.

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

Zhang C. | Morinaka K. | Kose M. | Ubukata T. | Yokoyama Y.

Article | 2019 | Beilstein Journal of Organic Chemistry15 , pp.2161 - 2169

Three new diarylethenes were synthesized from 1,2-bis(5-methyl-2-(4-substituted-phenyl)thiazol-4-yl)ethyne and benzyl azide through Ru(I)-catalyzed Huisgen cyclization reactions. The 4,5-bisthiazolyl-1,2,3-triazoles thus prepared, which belong to the terarylene family, showed thermally reversible photochromism. The absorption maximum wavelengths of the closed forms are longer than other terarylenes reported so far. The thermal back reactions are much faster when the substituents on the terminal phenyl groups are electron-withdrawing cyano groups than when they are electron-donating methoxy groups. © 2019 Zhang et al.

Kose, Mahmut | Sekerci, Cigdem Yildirim | Suzuki, Kazushi | Yokoyama, Yasushi

Article | 2011 | JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY219 ( 1 ) , pp.58 - 61

2,3-Bis(5-methyl-2-phenyl-4-thiazolyl)-1,4-naphthoquinone 1-O, its monoethylene acetal 2-O and methylated derivatives 3-O and 4-O were synthesized and their photochromic properties were investigated. While bisarylnaphthoquinone 1-O was nonphotochromic, its monoacetal 2-O and methylated derivatives 3-O and 4-O displayed good photochromism. Among them, the isomer 4-O recorded a remarkable diastereomeric excess (98.40%) with high conversion ratio (96.20%) upon UV irradiation. (C) 2011 Elsevier B.V. All rights reserved.

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