Köse M. | Orhan E.

Article | 2009 | Turkish Journal of Chemistry33 ( 5 ) , pp.579 - 588

New thermally stable photochromic fulgimides and benzimidazole[1,2-a]pyrrolidin-2-one derivatives of furylfulgide and thienylfulgide were prepared and their photochromic properties were investigated. Thermal stabilities of some of the new isomers in an alcoholic solution and in PMMA (poly(methyl methacrylate)) polymer films, and pyrolytic behaviors in inert atmosphere with TGA were compared. The colored form of fulgimide and that of benzimidazole[1,2-a]pyrrolidin-2-one derivatives showed large bathochromic shifts for visible absorption maximum compared with the colored form of corresponding fulgides. The imides and benzimidazole[1,2 . . .-a]pyrrolidin-2-one derivatives of fulgide displayed better thermal stability than corresponding fulgides. © TÜBİTAK Daha fazlası Daha az

Kose M. | Orhan E. | Büyükgüngör O.

Article | 2007 | Journal of Photochemistry and Photobiology A: Chemistry188 ( 02.Mar ) , pp.358 - 363

New thermally irreversible photochromic methyl cyanoacetate-condensed fulgide derivatives were prepared and their photochromic properties were investigated. Coloured form of methyl cyanoacetate-condensed derivatives C-4(a-d) show large bathochromic shifts of their long wavelength absorption bands compared to the coloured form of corresponding fulgides Z-1(a-d). Solvent effects on the compound ZZ-4a and its ring-closed form C-4a were investigated. The polarity of the solvent caused a bathochromic shift of both coloured and uncoloured forms. © 2007 Elsevier B.V. All rights reserved.

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

Kose M. | Orhan E.

Article | 2006 | Journal of Photochemistry and Photobiology A: Chemistry177 ( 02.Mar ) , pp.170 - 176

Novel photochromic benzimidazol[1,2a]pyrrolidin-2-ones, which give thermally stable highly coloured photochromes, have been synthesised by condensation of 2-methyl-3-benzothienylethylidene(isopropylidene) succinic anhydride with 1,2-diaminobenzene and its 4,5-dimethyl and 4,5-dimethoxy derivatives. The photochromic properties are reported. © 2005 Elsevier B.V. All rights reserved.

Yokoyama Y. | Kose M.

Review | 2004 | Journal of Photochemistry and Photobiology A: Chemistry166 ( 01.Mar ) , pp.9 - 18

Photochromism of thermally irreversible fulgides and diarylethenes can control not only the absorption spectra but also other chemical/physical properties by photoirradiation, such as supramolecular interaction to guest molecules, cholesteric liquid crystalline properties, and the chiroptical properties. The association constants originated from the triplex hydrogen bonds between the colored form of an indolylfulgimide and an acylated 2,6-bisaminopyridine increased when it was irradiated by visible light. The cholesteric pitch length was increased when a cholesteric liquid crystal composed of a mixture of the colored form of a binap . . .hthol-condensed indolylfulgide and a nematic liquid crystal was irradiated by visible light. An allylic 1,3-strain-controlled diastereoselective photochromic ring-closing reaction of a bisthienylethene showed as high as 88% diastereomer excess (de) with 85% conversion to the colored form in various solvents at room temperature. © 2004 Elsevier B.V. All rights reserved Daha fazlası Daha az

Kose M.

Article | 2004 | Journal of Photochemistry and Photobiology A: Chemistry165 ( 01.Mar ) , pp.97 - 102

New diarylethenes possessing one or two arenesulfinylethenyl moieties were casually synthesised. The photochromic and chiroptical properties of 1,2-bis-2-{2-methyl-5-[2-(4-toluenesulfinyl)ethenyl]-3- thienyl}-3,3,4,4,5,5-hexafluorocyclopentene were examined. While its colouring quantum yield by 313-nm irradiation (?O›C) was as large as 0.46, its bleaching quantum yield by 621-nm irradiation (?O›C) was negligibly small. Diels-Alder reaction of 2-(4-toluenesulfinyl)-1,4-benzoquinone with diarylethenes with the structure of 1-aryl-2-(5-ethenyl-2-methyl-3-thienyl)-3,3,4,4,5, 5-hexafluorocyclopentene gave, instead of the expected Diels-A . . .lder cycloadduct or its derivatives, 1-aryl-2-{2-methyl-5- [2-(4-toluenesulfinyl)ethenyl]-3-thienyl}-3,3,4,4,5, 5-hexafluorocyclopentene. © 2004 Elsevier B.V. All right reserved Daha fazlası Daha az

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