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Updated: Jul 21, 2026

Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction
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Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction

Published on: January 19, 2016

热可逆的 cis-cisoidal 到 cis-transoidal 异构化螺旋式型型多烯酸乙烯

Virgil Percec1, Jonathan G Rudick, Mihai Peterca

  • 1Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA. percec@sas.upenn.edu

Journal of the American Chemical Society
|October 27, 2005
PubMed
概括

树突化聚乙烯 (PPA) 聚合物形成螺旋状多孔柱,在加热后转化为非多孔结构. 这种受控的结构变化防止了原始PPA的退化,突出了它们的稳定性.

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Conformations of Cyclohexane

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The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
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Chair Conformation of Cyclohexane

The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
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Disubstituted Cyclohexanes: cis-trans Isomerism

Depending upon the different spatial orientation of the substituents, the disubstituted cycloalkanes exhibit two types of stereoisomers. The cis isomers have the substituents on the same side of the ring, whereas the trans isomers have the substituents on the opposite sides. These stereoisomers exhibit different physical properties and cannot be interconverted without breaking the carbon-carbon bonds.
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Stereoisomerism of Cyclic Compounds

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Stability of Conjugated Dienes

Introduction
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