Synthesis, Optical, and Electrochemical Properties of the High‐Molecular‐Weight Conjugated Polycarbazoles

Fu, Yaqin; Bo, Zhishan

doi:10.1002/marc.200500478

Cited by 50 publications

(31 citation statements)

References 30 publications

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“…The synthesis of the 2,7‐carbazole monomer has been reported previously . Seven different homopolymers were prepared using either Yamamoto or Suzuki polycondensation conditions (Table ), with molecular weights ranging from 4.6 kDa (a short chain oligomer comprised of 4 monomer units) to 91.7 kDa (corresponding to a degree of polymerization of 85). All polymers were highly soluble in a variety of organic solvents, including THF, toluene, xylenes, dichloromethane, and chloroform.…”

Section: Resultsmentioning

confidence: 99%

The effect of molecular weight on the separation of semiconducting single‐walled carbon nanotubes using poly(2,7‐carbazole)s

Rice

Subrahmanyam

Laengert

et al. 2015

J. Polym. Sci. Part A: Polym. Chem.

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The use of selective interactions between conjugated polymers and single‐walled carbon nanotubes has emerged as a promising method for the separation of nanotubes by electronic type. Although much attention has been devoted to investigating polyfluorenes and their ability to disperse semiconducting carbon nanotubes under specific conditions, other polymer families, such as poly(2,7‐carbazole)s, have been relatively overlooked. Poly(2,7‐carbazole)s have been shown to also preferentially interact with semiconducting carbon nanotubes, however a detailed investigation of polymer parameters, such as molecular weight, has not been performed. We have prepared seven different molecular weights of a poly(2,7‐carbazole), from short chain oligomers to high molecular weight polymers, and have investigated their effectiveness at dispersing semiconducting single‐walled carbon nanotubes. Although all polymer chain lengths were able to efficiently exfoliate carbon nanotube bundles using a mild dispersion protocol, only polymers above a certain threshold molecular weight (Mn ∼ 27 kDa) were found to exhibit complete selectivity for semiconducting nanotubes, with no observable signals from metallic species. Additionally, we found the quality of separation to be strongly dependent on the ratio of polymer to carbon nanotube. Contrary to previous reports, we have found that an excess of poly(2,7‐carbazole) leads to incomplete removal of metallic carbon nanotubes. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2510–2516

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Section: Resultsmentioning

confidence: 99%

The effect of molecular weight on the separation of semiconducting single‐walled carbon nanotubes using poly(2,7‐carbazole)s

Rice

Subrahmanyam

Laengert

et al. 2015

J. Polym. Sci. Part A: Polym. Chem.

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“…[ 16 ] The emission spectrum of 9-mer is quite close to that of the corresponding polymer, 2,7-linked poly(9-octylcarbazole). [ 17 ] The PL quantum yields of all oligomers in dilute toluene solutions were measured to be close to 100% by using 9,10-diphenylanthracene as a reference standard ( Φ F = 90%), indicating that 2,7-linked carbazole oligomers are highly effi cient emissive materials.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of 2,7‐Linked Carbazole Oligomers

Qin

2011

Macromol. Rapid Commun.

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A set of monodisperse 2,7-linked carbazole oligomers (3-mer, 5-mer, 7-mer, and 9-mer) was synthesized, and their photophysical, electrochemical, and thermal properties were investigated. In solutions, these oligomers exhibited bright blue emission with almost quantitative fluorescence quantum yield. The emission spectra of these oligomers in films are quite different. 3-Mer and 5-mer exhibited featureless emission spectra, whereas 7-mer and 9-mer showed well-resolved emission spectra.

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“…The synthesis of these 2,7‐linked carbazole oligomers was illustrated in Scheme . Q1 was synthesized according to published literature32; Synthesis of Q2 began by transfering 4,4′‐dibromobiphenyl to boronic ester compound 2 in a 76.8% yield. Compound 2 was then coupled to 4‐bromo‐1‐iodo‐2‐nitrobenzene monomer 3 by Suzuki–Miyaura cross‐coupling reaction to obtain four quantificational.…”

Section: Resultsmentioning

confidence: 99%

Carbazoles on same main chain for polymer solar cells

Qin

Jiang

et al. 2013

J of Applied Polymer Sci

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Planar conjugated 2,7-linked carbazole blocks: Q1(2,7-dibromo-9-octyl-9H-carbazole); Q2(7,7 0 -dibromo-9,9 0 -dioctyl-9H,9 0 H-2,2 0 -bicarbazole); Q3 (7-bromo-7 0 -(7-bromo-9-octyl-9H-carbazol-2-yl)-9,9 0 -dioctyl-9H,9 0 H-2,2 0 -bicarbazole) were coupled with same acceptor (4,7-di[2,5-thiophene]-5,6-dioctyloxy-2,1,3-Benzothiadiazole) to prepare polymers HXS-1, 2, 3 (Scheme 1). Bulkheterojunction polymer solar cells (BHJ PSCs) with these polymers were made. Power conversion efficiency of HXS-1 was proved to be over 5.4%. It declined dramatically to 0.43% and 0.23% for HXS-2 and 3 respectively. Their absorption and X-ray diffraction pattern show the torsion angle in main chain increased when more carbazole units were added. More carbazoles will make polycondensation reaction more difficult to get high molecular weight polymers. The torsion angle was calculated using a semiempirical molecular orbital method. All the results pointed out that the coplanarity in the conjugated backbone was destroyed. Electron delocalization was disturbed because p-orbital overlapping only occurs effectively in the parallel orbit so charge cannot move a longer distance. This study offers a useful and important insight to designing polymers for high performance PSCs.

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Synthesis, Optical, and Electrochemical Properties of the High‐Molecular‐Weight Conjugated Polycarbazoles

Cited by 50 publications

References 30 publications

The effect of molecular weight on the separation of semiconducting single‐walled carbon nanotubes using poly(2,7‐carbazole)s

The effect of molecular weight on the separation of semiconducting single‐walled carbon nanotubes using poly(2,7‐carbazole)s

Synthesis and Characterization of 2,7‐Linked Carbazole Oligomers

Carbazoles on same main chain for polymer solar cells

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