- Cyclo- N-alkyl-2,7-carbazoles: Influence of the Alkyl Chain Length on the Structural, Electronic, and Charge Transport Properties
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Macrocycles possessing radially oriented π-orbitals have experienced a fantastic development. However, their incorporation in organic electronic devices remains very scarce. In this work, we aim at bridging the gap between organic electronics and nanorings by reporting the first detailed structure-properties-device performance relationship study of organic functional materials based on a nanoring system. Three [4]cyclo-N-alkyl-2,7-carbazoles bearing different alkyl chains on their nitrogen atoms have been synthesized and characterized by combined experimental and theoretical approaches. This study includes electrochemical, photophysical, thermal, and structural solid-state measurements and charge transport properties investigations. An optimized protocol of the Pt approach has been developed to synthesize the [4]cyclocarbazoles in high yield (52-64%), of great interest for further development of nanorings, especially in materials science. The charge transport properties of [4]cyclocarbazoles and model compound [8]cycloparaphenylene ([8]CPP) have been studied. Although no field effect (FE) mobility was recorded for the benchmark [8]CPP, FE mobility values of ca. 10-5 cm2·V-1·s-1 were recorded for the [4]cyclocarbazoles. The characteristics (threshold voltage VTH, subthreshold swing SS, trapping energy ΔE) recorded for the three [4]cyclocarbazoles appear to be modulated by the alkyl chain length borne by the nitrogen atoms. Remarkably, the space-charge-limited current mobilities measured for the [4]cyclocarbazoles are about 3 orders of magnitude higher than that of [8]CPP (1.37/2.78 × 10-4 cm2·V-1·s-1 for the [4]cyclocarbazoles vs 1.21 × 10-7 cm2·V-1·s-1 for [8]CPP), highlighting the strong effect of nitrogen bridges on the charge transport properties. The whole study opens the way to the use of nanorings in electronics, which is now the next step of their development.
- Cornil, Jér?me,Donnio, Bertrand,Heinrich, Beno?t,Jacques, Emmanuel,Jeannin, Olivier,Lebreton, Christophe,Lucas, Fabien,McIntosh, Nemo,Poriel, Cyril,Quinton, Cassandre,Rault-Berthelot, Jo?lle
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supporting information
p. 8804 - 8820
(2021/06/28)
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- Carbazole-linked porphyrin dimers for organic light emitting diodes: Synthesis and initial photophysical studies
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Carbazole linked porphyrin dimers were synthesized in good yields via stepwise Suzuki coupling reactions using bromoporphyrins and borylated carbazoles as the precursors, the latter of which were synthesized via known procedures from biphenyl derivatives. For comparative purposes porphyrin-carbazole monomers were synthesized. Single layer organic light emitting diodes (OLEDs) were created to demonstrate the optical properties of these materials. Light emission from these carbazole substituted porphyrins showed better results compared to previously examined bromo substituted porphyrins with better electroluminescence and lower turn-on voltages. Dimers exhibited turn-on voltages of 3 V compared to 6 V for monomeric porphyrin-carbazoles.
- Ryan, Aoife,Tuffy, Brian,Horn, Sabine,Blau, Werner J.,Senge, Mathias O.
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p. 8248 - 8254
(2011/11/12)
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- Conjugated ladder-type heteroacenes bearing pyrrole and thiophene ring units: Facile synthesis and characterization
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(Chemical Equation Presented) Ladder-type heteroacenes containing pyrrole and thiophene rings, dibenzo[b,b′]thieno[2,3-f:5,4-f′]-carbazoles (DBTCZ, 1), and diindolo[3,2-b:2′,3′-h]benzo[1],2-b:4,5-b′] bis[1]benzothiophene (DIBBBT, 2), were facilely synthes
- Gao, Peng,Feng, Xinliang,Yang, Xiaoyin,Enkelmann, Volker,Baumgarten, Martin,Muellen, Klaus
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scheme or table
p. 9207 - 9213
(2009/04/11)
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