Journal
JOURNAL OF PHYSICAL CHEMISTRY C
Volume 117, Issue 51, Pages 27161-27166Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jp4104504
Keywords
-
Funding
- CINECA [HP10BFJG1H]
- University of Pavia
- CARIPLO Foundation
- MIUR PRIN [2009A5Y3N9]
- INSTM-Regione Lombardia
Ask authors/readers for more resources
The aggregation induced emission (AIE) behavior shown by organic chromophores is very interesting for the development of efficient solid state devices. The restriction of intramolecular rotation is by far the most frequently assumed mechanism to explain this behavior; by blocking or reducing this rotation, upon rigidification of the environment, molecular luminescence is restored. By means of ultrafast pump-probe spectroscopy combined with density functional theory (DFT) and time-dependent DFT calculations, we show direct evidence of intramolecular rotation in a simple push-pull organic chromophore,4-diethylamino-2 benzylidene malonic acid dimethyl ester, possessing AIE properties. The spectral evolution of the stimulated emission band of the chromophore in the first 45 ps after photoexcitation is fully consistent with the presence of a torsional relaxation toward the equilibrium geometry of the excited state, taking place on time scales that depend on the solvent viscosity. The structural features of the excited state fully account for the different photoluminescence efficiencies observed in solvents with different viscosities.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available