- Tuning J-aggregate Formation and Emission Efficiency in Cationic Diazapentacenium Dyes
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Enhancement of the luminescence efficiency of two new diazapentacenium salts (D1 and D2) of more than 55 for D1 and 22 times for D2) in poor solvents, acetonitrile and/or dichloromethane, was observed and rationalized as formation of emissive J-aggregates. Both compounds displaying 4-n-decylphenyl substituents at the 7,14-carbons and phenyl (D1) or 2,6-difluorophenyl (D2) substituents at the quaternary nitrogen atoms in 5,12-positions have been synthetized in a two-step procedure involving a two-fold Buchwald-Hartwig-type CN cross-coupling and an electrophilic Friedel-Crafts-type cyclization. The optical properties of the dicationic diazapentacenium salts in various solvents and in thin films have been investigated by steady-state and time-resolved absorption and photoluminescence spectroscopies. In thin films and in good solvents, isolated molecules coexist with aggregates. Nonetheless, D1 is seven times more emissive than D2, reflecting a higher J-aggregate contribution in the former.
- Rodrigues, Ana Clara B.,Wetterling, Dario,Scherf, Ullrich,Seixas de Melo, J. Sérgio
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supporting information
p. 7826 - 7830
(2021/05/07)
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- Synthesis of Di(hetero)arylamines from Nitrosoarenes and Boronic Acids: A General, Mild, and Transition-Metal-Free Coupling
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The synthesis of di(hetero)arylamines by a transition-metal-free cross-coupling between nitrosoarenes and boronic acids is reported. The procedure is experimentally simple, fast, mild, and scalable and has a wide functional group tolerance, including carbonyls, nitro, halogens, free OH and NH groups. It also permits the synthesis of sterically hindered compounds.
- Roscales, Silvia,Csák?, Aurelio G.
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supporting information
p. 1667 - 1671
(2018/03/23)
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