TY - JOUR
T1 - 4-Arylethynyl-5-fluorobenzoyl-1-methylimidazole Exhibiting Self-Recovering Mechanofluorochromism and Forming Fluorescence Molecular Glass
AU - Miura, Youhei
AU - Murai, Kazuki
AU - Yamada, Kazufumi
AU - Yoshioka, Naoki
N1 - Publisher Copyright:
© 2021 Chemical Society of Japan. All rights reserved.
PY - 2021
Y1 - 2021
N2 - 4-Arylethynyl-5-fluorobenzoyl-1-methyl-1H-imidazoles exhibited self-recovering mechanofluorochromism and formed a glass state. Although the solid sample of the anisyl-substituted 1a and dimethoxyphenyl-substituted 1b exhibited no and blue fluorescence, respectively, they exhibited bluish-green fluorescence after grinding. These compounds recovered the color of their fluorescence after approximately 20 s and after 20 h, respectively. Both compounds exhibited non-crystalline samples after melting and rapid cooling to room temperature. Based on thermal analysis, it was found 1a and 1b were supercooling liquid and glass, respectively, at room temperature. Both non-crystalline samples exhibited fluorescence at a wavelength longer than that of the solid state. DFT calculations indicated that the bluish-green fluorescence of the ground and noncrystalline samples was derived from the twisted intramolecular charge transfer excitation state.
AB - 4-Arylethynyl-5-fluorobenzoyl-1-methyl-1H-imidazoles exhibited self-recovering mechanofluorochromism and formed a glass state. Although the solid sample of the anisyl-substituted 1a and dimethoxyphenyl-substituted 1b exhibited no and blue fluorescence, respectively, they exhibited bluish-green fluorescence after grinding. These compounds recovered the color of their fluorescence after approximately 20 s and after 20 h, respectively. Both compounds exhibited non-crystalline samples after melting and rapid cooling to room temperature. Based on thermal analysis, it was found 1a and 1b were supercooling liquid and glass, respectively, at room temperature. Both non-crystalline samples exhibited fluorescence at a wavelength longer than that of the solid state. DFT calculations indicated that the bluish-green fluorescence of the ground and noncrystalline samples was derived from the twisted intramolecular charge transfer excitation state.
KW - Imidazole
KW - Mechanofluorochromism
KW - Molecular glass
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U2 - 10.1246/bcsj.20210247
DO - 10.1246/bcsj.20210247
M3 - Article
AN - SCOPUS:85134718487
SN - 0009-2673
VL - 94
SP - 2444
EP - 2450
JO - Bulletin of the Chemical Society of Japan
JF - Bulletin of the Chemical Society of Japan
IS - 10
ER -