Naslov
Direct Observation of Aggregation‐Induced Emission Mechanism

Autori
Guan, Jianxin ; Wei, Rong ; Prlj, Antonio ; Peng, Jie ; Lin, Kun‐Han ; Liu, Jitian ; Han, Han ; Corminboeuf, Clémence ; Zhao, Dahui ; Yu, Zhihao ; Zheng, Junrong

Izvornik
Angewandte Chemie International Edition (1433-7851) 59 (2020), 35; 14903-14909

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
aggregation-induced emission, conical intersections, luminescence, mechanism, ultrafast spectroscopy

Sažetak
The mechanism of aggregation-induced emission, which overcomes the common aggregation-caused quenching problem in organic optoelectronics, is revealed by monitoring the real time structural evolution and dynamics of electronic excited state with frequency and polarization resolved ultrafast UV/IR spectroscopy and theoretical calculations. The formation of Woodward-Hoffmann cyclic intermediates upon ultraviolet excitation is observed in dilute solutions of tetraphenylethylene and its derivatives but not in their respective solid. The ultrafast cyclization provides an efficient nonradiative relaxation pathway through crossing a conical intersection. Without such a reaction mechanism, the electronic excitation is preserved in the molecular solids and the molecule fluoresces efficiently, aided by the very slow intermolecular charge and energy transfers due to the well separated molecular packing arrangement. The mechanisms can be general for tuning the properties of chromophores in different phases for various important applications.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA