Mechano- and Photoresponsive Behavior of a Bis(cyanostyryl)benzene Fluorophore.
Chemistry
; 25(24): 6162-6169, 2019 Apr 26.
Article
en En
| MEDLINE
| ID: mdl-30860632
ABSTRACT
The mechanoresponsive behavior and photochemical response of a new bis(cyanostyryl)benzene fluorophore (CSB-5) were investigated. Green fluorescence with λem,max of 507â
nm was found for CSB-5 in chloroform solution, mirroring the behavior of a previously reported similar dye (CSB-6). Alternatively, crystalline samples of CSB-5 exhibited orange fluorescence with λem,max of 620â
nm, attributable to excimer emission. Although the emission color change was not clearly noticeable by naked eye, CSB-5 exhibited mechanochromic luminescence, due to transformation into the amorphous state upon grinding the crystalline powder. Interestingly, rubbed films of CSB-5 prepared on glass substrates exhibited a pronounced emission color change from orange to green when exposed to UV light. This response is the result of a photochemical reaction that occurs in the amorphous state and which causes a decrease of the excimer emission sites so that the emission color changes from excimer to monomer. The crystalline material did not display such a photoinduced emission color change and the difference in photochemical reactivity between crystalline and amorphous states was exploited to pattern the emission color of rubbed films.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Chemistry
Asunto de la revista:
QUIMICA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Japón