scholarly journals Restriction of the conrotatory motion in photo-induced 6π electrocyclic reaction: formation of the excited state of the closed-ring isomer in the cyclization

RSC Advances ◽  
2020 ◽  
Vol 10 (34) ◽  
pp. 20038-20045
Author(s):  
Tatsuhiro Nagasaka ◽  
Hikaru Sotome ◽  
Soichiro Morikawa ◽  
Lucas Martinez Uriarte ◽  
Michel Sliwa ◽  
...  
Keyword(s):  
Excited State ◽  
Molecular Geometry ◽  
Cyclization Reaction ◽  
Closed Ring ◽  
Electrocyclic Reaction ◽  
Reaction Formation

Restriction of the molecular geometry opens up a novel pathway in the cyclization reaction of a photochromic dithiazolylarylene derivative.

scholarly journals Photochromic diarylethene with turn-off fluorescent switching property

2019 ◽  
Author(s):  
Luna Kono ◽  
Yuma Nakagawa ◽  
Ayako Fujimoto ◽  
Ryo Nishimura ◽  
Yohei Hattori ◽  
...  
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Crystalline State ◽  
Uv Light ◽  
Stokes Shift ◽  
Intramolecular Proton Transfer ◽  
Light Irradiation ◽  
Aprotic Solvents ◽  
Uv Light Irradiation ◽  
Closed Ring

Background: Diarylethenes are well-known photochromic compounds, which undergo cyclization and cycloreversion reactions between open-　and closed-ring isomers. Recently, diarylethene derivatives with photoswitchable fluorescent properties were prepared. They are applicable for imaging and bio-imaging. On the other hand, new system called “excited state intramolecular proton transfer (ESIPT)” is reported. In the system, absorption and emission bands are divided due to the proton transfer, hence it showed strong fluorescence even in the crystalline state. We aimed to construct the photochromic system incorporating the ESIPT mechanism. Results: A diarylethene incorporating a fluorescent moiety that exhibit excited state intramolecular proton transfer (ESIPT) behavior was prepared. The ESIPT is one of the examples which express the mechanisms of aggregation-induced emission (AIE). This compound emits orange fluorescence with a large Stokes shift derived from ESIPT in aprotic solvents such as THF or hexane, while it exhibits only photochromic reaction in protic solvents such as methanol. In addition, it shows turn-off type fluorescence switching in an aprotic solvent and in crystals. The fluorescence is quenched as content of closed-ring isomers increases upon UV light irradiation. Conclusions: A diarylethene containing ESIPT functional group was prepared. It showed fluorescent turn-off behavior during photochromism in aprotic solvents as well as crystalline state upon UV light irradiation. Furthermore, it showed AIE in THF/water mixtures with blue-shift of the emission.

scholarly journals A leaning amine–ketone dyad with a nonconjugated linker: solvatofluorochromism and dual fluorescence associated with intramolecular charge transfer

2018 ◽  
Vol 17 (9) ◽  
pp. 1157-1168 ◽  
Author(s):  
Yutaro Kuramoto ◽  
Takanobu Nakagiri ◽  
Yasunori Matsui ◽  
Eisuke Ohta ◽  
Takuya Ogaki ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Molecular Geometry ◽  
Dual Fluorescence

A amine–ketone dyad with a nonconjugated linker displays solvatofluorochromism and dual fluorescence due to intramolecular charge transfer in the excited state accompanied by a change of the molecular geometry like leaning.

Sign in / Sign up

Export Citation Format

Share Document