Circularly Polarized Electroluminescence from Liquid-Crystalline Chiral Polyfluorenes

Oda, Masanao; Nothofer, Heinz‐Georg; Lieser, Günter; Scherf, Ullrich; Meskers, Stefan C. J.; Neher, Dieter

doi:10.1002/(sici)1521-4095(200003)12:5<362::aid-adma362>3.0.co;2-p

Cited by 296 publications

(265 citation statements)

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“…4 Chiroptical properties, such as circular dichroism (CD), optical rotation, and circular polarized luminescence, enrich the applications of these organic semiconductors as optical devices or sensors. [5][6][7][8][9] Optically active side chains may introduce chiroptical properties into conjugated polymers, but some polymers exhibit these properties only in films or phase separating solutions, [10][11][12][13] which indicates that intermolecular chiral interactions are necessary to induce the chiroptical properties in such conjugated polymers.…”

Section: Introductionmentioning

confidence: 99%

Double screw-sense inversions of helical chiral-achiral random copolymers of fluorene derivatives in phase separating solutions

Sanada

Terao

Sato

2011

Polym J

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The addition of methanol to dilute THF solutions of chiral-achiral random copolymers of fluorene derivatives and the chiral homopolymer showed thermo-reversible circular dichroism (CD) induction in the main-chain fluorene absorption region. This finding demonstrated the uneven population of the right-and left-handed helical conformations in the polymer chains. From the sign of the induced CD, two helical screw-sense inversions were found by changing the chiral monomer content. The Ising model for chirally interacting chiral-achiral random copolymers can explain the double screw-sense inversions.

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Section: Introductionmentioning

confidence: 99%

Double screw-sense inversions of helical chiral-achiral random copolymers of fluorene derivatives in phase separating solutions

Sanada

Terao

Sato

2011

Polym J

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“…The prominent functions of these biological components have motivated chemists to design artificial helical architectures (1)(2)(3)(4)(5)(6)(7)(8), which can be used for a variety of applications such as chiral separation (9,10) and sensing (11)(12)(13)(14)(15), asymmetric synthesis (16), liquid crystals (17)(18)(19), nonlinear optics (20,21), and so forth. Recently, a hot issue of chirality has emerged in relation to the helicity of the hexagonal carbon lattice in carbon nanotubes, because it determines the conductive properties of carbon nanotubes (22)(23)(24).…”

mentioning

confidence: 99%

Self-assembled graphitic nanotubes with one-handed helical arrays of a chiral amphiphilic molecular graphene

Jin

Fukushima²,

Niki³

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

259

177

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Self-assembly of a Gemini-shaped, chiral amphiphilic hexa-perihexabenzocoronene having two chiral oxyalkylene side chains, along with two lipophilic side chains, yields graphitic nanotubes with one-handed helical chirality. The nanotubes are characterized by an extremely high aspect ratio of >1,000 and have a uniform diameter of 20 nm and a wall thickness of 3 nm. The nanotubes with right-and left-handed helical senses were obtained from the (S)-and (R)-enantiomers of the amphiphile, respectively, due to an efficient translation of point chirality into supramolecular helical chirality. The (S)-and (R)-enantiomers coassemble at varying mole ratios to give nanotubes, whose circular dichroism profiles are almost unchanged over a wide range of the enantiomeric excess of the amphiphile (100 -20%). The high level of chirality amplification thus observed indicates a long-range cooperativity in the selfassembling process. In sharp contrast, a hexabenzocoronene amphiphile with chiral lipophilic side chains did not form nanotubular assemblies. The present work demonstrates the majority rule in noncovalent systems and also may provide a synthetic strategy toward realization of molecular solenoids. chirality ͉ self-assembly H elicity is one of the most essential structural elements for certain biomolecules such as peptides and DNA. The prominent functions of these biological components have motivated chemists to design artificial helical architectures (1-8), which can be used for a variety of applications such as chiral separation (9, 10) and sensing (11-15), asymmetric synthesis (16), liquid crystals (17-19), nonlinear optics (20, 21), and so forth. Recently, a hot issue of chirality has emerged in relation to the helicity of the hexagonal carbon lattice in carbon nanotubes, because it determines the conductive properties of carbon nanotubes (22-24). Conductive polymers with helical architectures (25) also have attracted attention in view of the concept of molecular solenoids (26,27), although this concept has yet been a dream of scientists, because there are no molecular objects that fulfill certain requisites for conductivity and helicity. Here, we report an example of conductive tubular objects consisting of one-handed helical arrays of a -stacked chiral molecular graphene. Self-assembly of hexa-peri-hexabenzocoronene (HBC) derivatives to form discotic liquid crystals and nanofibers has been studied extensively by Müllen and coworkers (28,29). We recently found that an amphiphilic HBC derivative (1) (Fig. 1) self-assembles in polar organic solvents such as tetrahydrofuran (THF) to give graphitic nanotubes, whose wall consists of a bilayer tape formed from bilaterally coupled columns of -stacked HBC units (30). In the course of this work, we have noticed that the self-assembly of 1, although achiral, gives a mixture of coiled and tubular assemblies under certain conditions, suggesting that the tubular objects also bear a helical structural element. This observation prompted us to design chiral HBC amphiphiles 2 and 3 (Fi...

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“…Elaboration of enantiopure (M)- [6]helicenebisquinone 12 into (M)- [8]helicene 13 with complete transfer of ee was reported ( Figure 15.5) [63]. [8]Helicene 13 is the longest enantiopure helicene prepared via nonphotochemical synthesis.…”

Section: Annelation Of Racemic Intermediate Leading To Racemic [N]helmentioning

confidence: 96%

“…Numerous [n]helicenes (n ≤ 13) and [n]thiahelicenes (n ≤ 13) were obtained in non-racemic form via the following methods: (1) seeded crystallization of con glomerate (e.g. [7]-, [8]-, and [9]helicene) [46,47], (2) resolution by chromatography (e.g. [13]thiahelicene) [48] and (3) photocyclization from a resolved precursor (e.g.…”

Section: Photochemical Synthesesmentioning

confidence: 99%

“…Another aspect of the design involves optimization of chiral counterparts of properties in optics (circular polarization of light), electronics (chiral transport of charge carriers), etc. [6][7][8][9][10][11]. The challenge in this area is to obtain materials with inherently strong chiral properties at the macromolecular level, rather than derived from an aggre gate or a supramolecular structure.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and Characterization of Novel Chiral Conjugated Materials

Rajca

Miyasaka

2006

Functional Organic Materials

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Circularly Polarized Electroluminescence from Liquid-Crystalline Chiral Polyfluorenes

Cited by 296 publications

References 0 publications

Double screw-sense inversions of helical chiral-achiral random copolymers of fluorene derivatives in phase separating solutions

Double screw-sense inversions of helical chiral-achiral random copolymers of fluorene derivatives in phase separating solutions

Self-assembled graphitic nanotubes with one-handed helical arrays of a chiral amphiphilic molecular graphene

Synthesis and Characterization of Novel Chiral Conjugated Materials

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