Journal ArticleDOI
Synthesis of Single-Handed Helical Spiro-Conjugated Ladder Polymers through Quantitative and Chemoselective Cyclizations*.
TLDR
In this article, the spiro-linked dibenzo[ a, h ]anthracene fluorophores are arranged in a one-handed twisting direction, through quantitative and chemoselective acid-promoted intramolecular cyclizations of random-coil precursor polymers composed of chiral 1,1'-spirobiindane and achiral bis[2-(4-alkoxyphenyl)ethynyl]phenylene units.Abstract:
We report the unprecedented synthesis of one-handed helical spiro-conjugated ladder polymers with well-defined primary and secondary structures, in which the spiro-linked dibenzo[ a , h ]anthracene fluorophores are arranged in a one-handed twisting direction, through quantitative and chemoselective acid-promoted intramolecular cyclizations of random-coil precursor polymers composed of chiral 1,1'-spirobiindane and achiral bis[2-(4-alkoxyphenyl)ethynyl]phenylene units. Intense circular dichroism (CD) and circularly polarized luminescence (CPL) were observed, whereas the precursor polymers exhibited negligible CD and CPL activities. The introduction of 2,6-dimethyl substituents on the 4-alkoxyphenylethynyl pendants is of key importance for this simple, quantitative, and chemoselective cyclization. This strategy is applicable to the defect-free precise synthesis of other varieties of fully π-conjugated molecules and coplanar ladder polymers that have not been achieved before.read more
Citations
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Journal ArticleDOI
Brightening up Circularly Polarized Luminescence of Monosubstituted Polyacetylene by Conformation Control: Mechanism, Switching, and Sensing
Sheng Wang,Deping Hu,Xiaoyan Guan,Siliang Cai,Ge Shi,Zhigang Shuai,Jie Zhang,Qian Peng,Xinhua Wan +8 more
TL;DR: In this paper, the first example of luminescent monosubstituted polyacetylenes (mono-PAs) is presented, based on a contracted cis-cisoid polyene backbone.
Journal ArticleDOI
Advances in circularly polarized luminescent materials based on axially chiral compounds
TL;DR: In this article , the development status of axially chiral compounds with CPL properties from two aspects of photoluminecence and electroluminescence, covering metal complexes, polymers, supramolecular assemblies, simple organic molecules, and liquid crystals systems.
Journal ArticleDOI
Consecutively fused single‐, double‐, and triple‐expanded helicenes
TL;DR: In this article , a defect-free C-shaped single and S- and M-shaped consecutively fused double-and triple-expanded homochiral helicenes (all-right (P) or all-left (M) handed) were obtained by using trifluoroacetic acid-promoted intramolecular multistep cascade alkyne benzannulations.
Journal ArticleDOI
Symmetrically Tetra‐functionalized Pillar[6]arenes Prepared by Fragment Coupling
Hao Xing,Igor Diemberger +1 more
TL;DR: In this paper , a two-step fragment coupling method has been developed for synthesizing symmetrically tetra-functionalized pillar[6]arenes, namely X-pillar[6]-arenes.
Journal ArticleDOI
Single-Handed Helicene Nanoribbons via Transfer of Chiral Information.
Xiao Xiao,Qian Cheng,Si Tong Bao,Zexin Jin,Shantao Sun,Hao Jiang,Michael L. Steigerwald,Colin Nuckolls +7 more
TL;DR: In this article , single-handed helicene nanoribbons were synthesized with different ratios of [6]helicene "sergeants" to [5]-helicenes "soldiers", which on average consist of between ∼50 and 60 ortho-annulated benzene rings.
References
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Journal ArticleDOI
Supramolecular Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions
TL;DR: The recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of their formations with unique chiral phenomena, such as amplification of chirality during the dynamic helically assembled processes, properties, and specific functionalities.
Journal ArticleDOI
Gas Permeation Properties, Physical Aging, and Its Mitigation in High Free Volume Glassy Polymers
TL;DR: This review addresses the need to compare the approaches to achieving the best performance in order to identify their effectiveness in improving gas transport properties and in mitigating aging, and provides perspectives on a few key aspects of research related to high free volume polymer membranes.
Journal ArticleDOI
Directed Electrophilic Cyclizations - Efficient Methodology for the Synthesis of Fused Polycyclic Aromatics
TL;DR: In this paper, a two-step synthesis of complex, fused polycyclic aromatic systems using Suzuki and Negishi type cross-coupling chemistries is described, where the critical ring-forming step uses 4-alkoxyphenylethynyl groups and is induced by strong electrophiles such as trifluoroacetic acid and iodonium tetrafluoroborate.
Journal ArticleDOI
Precision synthesis versus bulk-scale fabrication of graphenes
TL;DR: Graphene is a fascinating material with unique properties, such as extreme mechanical strength, ultrahigh electrical and thermal conductivities and remarkable transparency as mentioned in this paper, which makes it attractive as next-generation semiconductors.
Journal ArticleDOI
Fused Polycyclic Aromatics via Electrophile-Induced Cyclization Reactions: Application to the Synthesis of Graphite Ribbons
TL;DR: In this article, an all-carbon conjugated ladder polymer or graphite ribbon was synthesized using an electrophile-induced cyclization reaction which provides a powerful new route to fused benzenoid aromatic hydrocarbon systems.
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