Carbazole dendrons

A. Kimoto, J. Cho, M. Higuchi, and K. Yamamoto, Synthesis of asymmetrically arranged dendrimers with a carbazole dendron and a phenylazomethine dendron, Macromolecules, 37 5531-5537 (2004). 

Dehaen and coworkers utiUzed carbazole dendrons attached to 1,10-phenanthroline ligands (phen) to construct a dendrimer around a Ru(ll) core (12, Scheme 6) (12]. Absorbance transitions assigned to carbazole, phen, and carbazole-to-phen CT transitions aU gave rise to emission from the Ru(ll) core, providing yet another hght-harvesting dendrimer, which illustrates the antennae effect. 

Scheme 27 Porphyrin core dendrimers with carbazole dendrons by Dehaen [78] (top) and Lu [79] (bottom)... 

FIGURE 5.7 Second-generation irido-dendrimers with carbazole dendrons used for the formation of highly efficient green light- (left) and red light (ng/ Remitting diodes. 

ZhaoZH, Jin H, Zhang YX, ShenZ (2011) Synthesis and properties of dendritic emitters with a fluorinated starburst oxadiazole core and twisted carbazole dendrons. Macromolecules 44 1405-1413... 

Recently, Bo and coworkers [317] reported on dendronized PF with carbazole end groups in the peripheral Frechet-type dendrons 214a-c. Polymers emitted blue light with high < pL of 86-96% in solution for all three polymers 214a-c (G0-G2). In the solid state, < PL depended on the size of the attached dendron (29, 55, and 64% for GO, Gl, and G2, respectively) (Chart 2.50). 

Y. Fu, J. Li, S. Yan, and Z. Bo, High molecular weight dendronized poly(fluorene)s with peripheral carbazole groups synthesis, characterization, and properties, Macromolecules, 37 6395-6400, 2004. 

Tian and co-workers have prepared and investigated the properties of flexible dendrons and dendrimers that have NI or PDI cores with carbazole (CZ) or oxadiazole (OXZ) peripheral units (Scheme 38) [103,104]. Excitation of the peripheral chromophores result in emission of the NI of PDI cores. Interestingly, in the case of the NI core dendrons, excitation of the peripheral oxadiazole residues of 75c results in a 3.9 times enhancement of core liuni-nescence, while excitation of the peripheral carbazole residues of 76c results in only a 20% emission intensity, suggesting a second pathway for donor quenching in the CZ systems. This pathway is probably photo-induced electron transfer (PET) from the CZ units to the NI core [104], The OXZ units, however, have a relatively higher electron affinity and no PET can take place. 

Peng, Q., Xu, ]., Li, M., Zheng, W., 2009. Blue emitting polyfiuorenes containing dendronized carbazole and oxadiazole pendants synthesis, optical properties, and electroluminescent properties. Macromolecules 42, 5478-5485. 

The brief presents a systematic study of synthesis of optically active polymers. It discusses in detail about the syntheses of three different types of optically active polymers from helical polymers, dendronized polymers and other types of polymeric compounds. The brief also explains the syntheses of optically active azoaromatic and carbazole containing azoaromatic polymers and copolymers optically active benzodithiophene and optically active porphyrin derivatives. The final chapter of the brief discusses different properties of optically active polymers such as nonlinear optical properties, chiroptical properties, vapochromic behavior, absorption and emission properties, fabrication and photochromic properties. The intrinsic details of different properties of optically active polymers will be useful for researchers and industry personnel, who are actively engaged in application oriented investigations. 

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