Molecular curvature, specific intermolecular interactions and the twist-bend nematic phase: the synthesis and characterisation of the 1-(4-cyanobiphenyl-4-yl)-6-(4-alkylanilinebenzylidene-4-oxy)hexanes (CB6O.m)

Rebecca Walker, Damian Pociecha, Grant J Strachan, John M D Storey, Ewa Gorecka, Corrie T Imrie (Corresponding Author)

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7 Citations (Scopus)

Abstract

The syntheses and characterisation of the first ten homologues of the 1-(4-cyanobiphenyl-4-yl)-6-(4-alkylanilinebenzylidene-4-oxy)hexanes (CB6O.m) are reported. All ten members of the series exhibit an enantiotropic nematic, N, phase, and a monotropic twist-bend nematic, N-TB, phase. Only CB6O.10 shows a smectic phase. The assignment of both nematic phases was confirmed using X-ray diffraction. For short chain lengths (m = 1-6) the local packing in both nematic phases is an intercalated arrangement, for intermediate chain lengths a frustrated local structure is seen and for the longest chain length, a bilayer arrangement is observed. This change in the local structure on increasing m has no apparent effect on the stability of either nematic phase, and TNTBN and T-NI show a regular dependence on m. Specifically, TNTBN and T-NI decrease on increasing m and superimposed upon this is a weak odd-even effect in which the odd members show the higher values. T-NI decreases more rapidly than TNTBN on increasing m such that the ratio TNTBN/T-NI increases. The lower temperature liquid crystal phase shown by 1-(4-cyanobiphenyl-4-yloxy)-5-(4-butylanilinebenzylidene-4-oxy)pentane (CBO5O.4) is reassigned as a twist-bend nematic phase. The transitional properties of the CB6O.m, CB6O.Om and CBO5O.m series are compared.

Original languageEnglish
Pages (from-to)3188-3197
Number of pages10
JournalSoft matter
Volume15
Early online date11 Mar 2019
DOIs
Publication statusPublished - 21 Apr 2019

Fingerprint

Hexanes
Chain length
curvature
synthesis
Liquid Crystals
pentanes
interactions
liquid crystals
X ray diffraction
diffraction
x rays
Temperature

Keywords

  • LIQUID-CRYSTAL DIMERS
  • TRANSITIONAL PROPERTIES
  • MESOMORPHIC BEHAVIOR
  • MESOPHASE
  • OLIGOMERS
  • DEPENDENCE
  • COMPOUND
  • MIXTURES
  • GEOMETRY
  • TRIMERS

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Chemistry(all)

Cite this

@article{19487bf93b42467ba6ce9262e87835ee,
title = "Molecular curvature, specific intermolecular interactions and the twist-bend nematic phase: the synthesis and characterisation of the 1-(4-cyanobiphenyl-4-yl)-6-(4-alkylanilinebenzylidene-4-oxy)hexanes (CB6O.m)",
abstract = "The syntheses and characterisation of the first ten homologues of the 1-(4-cyanobiphenyl-4-yl)-6-(4-alkylanilinebenzylidene-4-oxy)hexanes (CB6O.m) are reported. All ten members of the series exhibit an enantiotropic nematic, N, phase, and a monotropic twist-bend nematic, N-TB, phase. Only CB6O.10 shows a smectic phase. The assignment of both nematic phases was confirmed using X-ray diffraction. For short chain lengths (m = 1-6) the local packing in both nematic phases is an intercalated arrangement, for intermediate chain lengths a frustrated local structure is seen and for the longest chain length, a bilayer arrangement is observed. This change in the local structure on increasing m has no apparent effect on the stability of either nematic phase, and TNTBN and T-NI show a regular dependence on m. Specifically, TNTBN and T-NI decrease on increasing m and superimposed upon this is a weak odd-even effect in which the odd members show the higher values. T-NI decreases more rapidly than TNTBN on increasing m such that the ratio TNTBN/T-NI increases. The lower temperature liquid crystal phase shown by 1-(4-cyanobiphenyl-4-yloxy)-5-(4-butylanilinebenzylidene-4-oxy)pentane (CBO5O.4) is reassigned as a twist-bend nematic phase. The transitional properties of the CB6O.m, CB6O.Om and CBO5O.m series are compared.",
keywords = "LIQUID-CRYSTAL DIMERS, TRANSITIONAL PROPERTIES, MESOMORPHIC BEHAVIOR, MESOPHASE, OLIGOMERS, DEPENDENCE, COMPOUND, MIXTURES, GEOMETRY, TRIMERS",
author = "Rebecca Walker and Damian Pociecha and Strachan, {Grant J} and Storey, {John M D} and Ewa Gorecka and Imrie, {Corrie T}",
note = "EG and DP acknowledge the support of the National Science Centre (Poland): (Grant Number 2016/22/A/ST5/00319). RW gratefully acknowledges The Carnegie Trust for the Universities of Scotland for funding the award of a PhD scholarship.",
year = "2019",
month = "4",
day = "21",
doi = "10.1039/c9sm00026g",
language = "English",
volume = "15",
pages = "3188--3197",
journal = "Soft matter",
issn = "1744-683X",
publisher = "ROYAL SOC CHEMISTRY",

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TY - JOUR

T1 - Molecular curvature, specific intermolecular interactions and the twist-bend nematic phase

T2 - the synthesis and characterisation of the 1-(4-cyanobiphenyl-4-yl)-6-(4-alkylanilinebenzylidene-4-oxy)hexanes (CB6O.m)

AU - Walker, Rebecca

AU - Pociecha, Damian

AU - Strachan, Grant J

AU - Storey, John M D

AU - Gorecka, Ewa

AU - Imrie, Corrie T

N1 - EG and DP acknowledge the support of the National Science Centre (Poland): (Grant Number 2016/22/A/ST5/00319). RW gratefully acknowledges The Carnegie Trust for the Universities of Scotland for funding the award of a PhD scholarship.

PY - 2019/4/21

Y1 - 2019/4/21

N2 - The syntheses and characterisation of the first ten homologues of the 1-(4-cyanobiphenyl-4-yl)-6-(4-alkylanilinebenzylidene-4-oxy)hexanes (CB6O.m) are reported. All ten members of the series exhibit an enantiotropic nematic, N, phase, and a monotropic twist-bend nematic, N-TB, phase. Only CB6O.10 shows a smectic phase. The assignment of both nematic phases was confirmed using X-ray diffraction. For short chain lengths (m = 1-6) the local packing in both nematic phases is an intercalated arrangement, for intermediate chain lengths a frustrated local structure is seen and for the longest chain length, a bilayer arrangement is observed. This change in the local structure on increasing m has no apparent effect on the stability of either nematic phase, and TNTBN and T-NI show a regular dependence on m. Specifically, TNTBN and T-NI decrease on increasing m and superimposed upon this is a weak odd-even effect in which the odd members show the higher values. T-NI decreases more rapidly than TNTBN on increasing m such that the ratio TNTBN/T-NI increases. The lower temperature liquid crystal phase shown by 1-(4-cyanobiphenyl-4-yloxy)-5-(4-butylanilinebenzylidene-4-oxy)pentane (CBO5O.4) is reassigned as a twist-bend nematic phase. The transitional properties of the CB6O.m, CB6O.Om and CBO5O.m series are compared.

AB - The syntheses and characterisation of the first ten homologues of the 1-(4-cyanobiphenyl-4-yl)-6-(4-alkylanilinebenzylidene-4-oxy)hexanes (CB6O.m) are reported. All ten members of the series exhibit an enantiotropic nematic, N, phase, and a monotropic twist-bend nematic, N-TB, phase. Only CB6O.10 shows a smectic phase. The assignment of both nematic phases was confirmed using X-ray diffraction. For short chain lengths (m = 1-6) the local packing in both nematic phases is an intercalated arrangement, for intermediate chain lengths a frustrated local structure is seen and for the longest chain length, a bilayer arrangement is observed. This change in the local structure on increasing m has no apparent effect on the stability of either nematic phase, and TNTBN and T-NI show a regular dependence on m. Specifically, TNTBN and T-NI decrease on increasing m and superimposed upon this is a weak odd-even effect in which the odd members show the higher values. T-NI decreases more rapidly than TNTBN on increasing m such that the ratio TNTBN/T-NI increases. The lower temperature liquid crystal phase shown by 1-(4-cyanobiphenyl-4-yloxy)-5-(4-butylanilinebenzylidene-4-oxy)pentane (CBO5O.4) is reassigned as a twist-bend nematic phase. The transitional properties of the CB6O.m, CB6O.Om and CBO5O.m series are compared.

KW - LIQUID-CRYSTAL DIMERS

KW - TRANSITIONAL PROPERTIES

KW - MESOMORPHIC BEHAVIOR

KW - MESOPHASE

KW - OLIGOMERS

KW - DEPENDENCE

KW - COMPOUND

KW - MIXTURES

KW - GEOMETRY

KW - TRIMERS

UR - http://www.scopus.com/inward/record.url?scp=85064172033&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/molecular-curvature-specific-intermolecular-interactions-twistbend-nematic-phase-synthesis-character

UR - http://dx.doi.org/10.1039/c9sm00026g

U2 - 10.1039/c9sm00026g

DO - 10.1039/c9sm00026g

M3 - Article

VL - 15

SP - 3188

EP - 3197

JO - Soft matter

JF - Soft matter

SN - 1744-683X

ER -