A liquid-crystalline silsesquioxane dendrimer exhibiting chiral nematic and columnar mesophases

I M  Saez; J W  Goodby; R M  Richardson

doi:10.1002/1521-3765(20010702)7:13<2758::AID-CHEM2758>3.0.CO;2-T

A liquid-crystalline silsesquioxane dendrimer exhibiting chiral nematic and columnar mesophases

I M Saez, J W Goodby, R M Richardson

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

A hexadecamer, first-generation, octasilsesquioxane liquid-crystalline dendrimer was synthesized by a platinum-catalyzed hydrosilylation reaction of the parent first-generation vinyl octasilsesquioxane dendrimer with a modified, laterally substituted mesogen. The structure and purity of the octasilsesquioxane substrate was confirmed by H-1, C-13, and (29) Si NMR spectroscopy, microanalysis, and size exclusion chromatography (SEC). The mesogenic substrate was found to exhibit only a chiral nematic phase, whereas the resulting hexadecamer dendrimer displays enantiotropic chiral nematic, disordered hexagonal columnar, and disordered rectangular columnar phases, with a glass transition below room temperature. The lateral or side-on attachment of the mesogen to the dendritic core was found to be a key design feature in the formation of the mesophases.

Original language	English
Pages (from-to)	2758-2764
Number of pages	7
Journal	Chemistry - A European Journal
Volume	7
Issue number	13
DOIs	https://doi.org/10.1002/1521-3765(20010702)7:13<2758::AID-CHEM2758>3.0.CO;2-T
Publication status	Published - 2 Jul 2001

Keywords

chiral nematic phases
columnar phases
dendrimers
liquid crystals
silsesquioxane
SIDE-CHAIN POLYMERS
SUPRAMOLECULAR DENDRIMERS
THERMOTROPIC MESOPHASES
CARBOSILANE DENDRIMERS
STILBENOID DENDRIMERS
MESOGENIC GROUPS
GENERATION
DENDROMESOGENS
MACROMOLECULES
DIFFRACTION

Access to Document

10.1002/1521-3765(20010702)7:13<2758::AID-CHEM2758>3.0.CO;2-T

http://dx.doi.org/10.1002/1521-3765(20010702)7:13<2758::AID-CHEM2758>3.0.CO;2-T

Cite this

@article{efb2e7ed39514c59a948999d3fb39fb2,

title = "A liquid-crystalline silsesquioxane dendrimer exhibiting chiral nematic and columnar mesophases",

abstract = "A hexadecamer, first-generation, octasilsesquioxane liquid-crystalline dendrimer was synthesized by a platinum-catalyzed hydrosilylation reaction of the parent first-generation vinyl octasilsesquioxane dendrimer with a modified, laterally substituted mesogen. The structure and purity of the octasilsesquioxane substrate was confirmed by H-1, C-13, and (29) Si NMR spectroscopy, microanalysis, and size exclusion chromatography (SEC). The mesogenic substrate was found to exhibit only a chiral nematic phase, whereas the resulting hexadecamer dendrimer displays enantiotropic chiral nematic, disordered hexagonal columnar, and disordered rectangular columnar phases, with a glass transition below room temperature. The lateral or side-on attachment of the mesogen to the dendritic core was found to be a key design feature in the formation of the mesophases.",

keywords = "chiral nematic phases, columnar phases, dendrimers, liquid crystals, silsesquioxane, SIDE-CHAIN POLYMERS, SUPRAMOLECULAR DENDRIMERS, THERMOTROPIC MESOPHASES, CARBOSILANE DENDRIMERS, STILBENOID DENDRIMERS, MESOGENIC GROUPS, GENERATION, DENDROMESOGENS, MACROMOLECULES, DIFFRACTION",

author = "Saez, {I M} and Goodby, {J W} and Richardson, {R M}",

year = "2001",

month = jul,

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doi = "10.1002/1521-3765(20010702)7:13<2758::AID-CHEM2758>3.0.CO;2-T",

language = "English",

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journal = "Chemistry : A European Journal",

issn = "0947-6539",

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TY - JOUR

T1 - A liquid-crystalline silsesquioxane dendrimer exhibiting chiral nematic and columnar mesophases

AU - Saez, I M

AU - Goodby, J W

AU - Richardson, R M

PY - 2001/7/2

Y1 - 2001/7/2

N2 - A hexadecamer, first-generation, octasilsesquioxane liquid-crystalline dendrimer was synthesized by a platinum-catalyzed hydrosilylation reaction of the parent first-generation vinyl octasilsesquioxane dendrimer with a modified, laterally substituted mesogen. The structure and purity of the octasilsesquioxane substrate was confirmed by H-1, C-13, and (29) Si NMR spectroscopy, microanalysis, and size exclusion chromatography (SEC). The mesogenic substrate was found to exhibit only a chiral nematic phase, whereas the resulting hexadecamer dendrimer displays enantiotropic chiral nematic, disordered hexagonal columnar, and disordered rectangular columnar phases, with a glass transition below room temperature. The lateral or side-on attachment of the mesogen to the dendritic core was found to be a key design feature in the formation of the mesophases.

AB - A hexadecamer, first-generation, octasilsesquioxane liquid-crystalline dendrimer was synthesized by a platinum-catalyzed hydrosilylation reaction of the parent first-generation vinyl octasilsesquioxane dendrimer with a modified, laterally substituted mesogen. The structure and purity of the octasilsesquioxane substrate was confirmed by H-1, C-13, and (29) Si NMR spectroscopy, microanalysis, and size exclusion chromatography (SEC). The mesogenic substrate was found to exhibit only a chiral nematic phase, whereas the resulting hexadecamer dendrimer displays enantiotropic chiral nematic, disordered hexagonal columnar, and disordered rectangular columnar phases, with a glass transition below room temperature. The lateral or side-on attachment of the mesogen to the dendritic core was found to be a key design feature in the formation of the mesophases.

KW - chiral nematic phases

KW - columnar phases

KW - dendrimers

KW - liquid crystals

KW - silsesquioxane

KW - SIDE-CHAIN POLYMERS

KW - SUPRAMOLECULAR DENDRIMERS

KW - THERMOTROPIC MESOPHASES

KW - CARBOSILANE DENDRIMERS

KW - STILBENOID DENDRIMERS

KW - MESOGENIC GROUPS

KW - GENERATION

KW - DENDROMESOGENS

KW - MACROMOLECULES

KW - DIFFRACTION

U2 - 10.1002/1521-3765(20010702)7:13<2758::AID-CHEM2758>3.0.CO;2-T

DO - 10.1002/1521-3765(20010702)7:13<2758::AID-CHEM2758>3.0.CO;2-T

M3 - Article

SN - 0947-6539

VL - 7

SP - 2758

EP - 2764

JO - Chemistry : A European Journal

JF - Chemistry : A European Journal

IS - 13

ER -