Chiral conflict. The effect of temperature on the helical sense of a polymer controlled by the competition between structurally different enantiomers: From dilute solution to the lyotropic liquid crystal state

Kai Tang, Mark M. Green, Kap Soo Cheon, Jonathan V. Selinger, Bruce Garetz

Research output: Contribution to journalArticle

Abstract

Helical polymers appended with paired structurally different enantiomers, which have opposing helical sense preferences, yield a new kind of relationship between optical activity and temperature, and also reveal unusual details of the nature of chiral interactions. Consistent with a statistical physical theory developed for these experiments, the proportion of the competing chiral groups, determined by synthesis, fixes the compensation temperature at which the helical senses are equally populated. The lyotropic liquid crystal state formed by these polymers yields therefore a nematic state at any chosen temperature over a very wide range, with a cholesteric state arising with tightening pitch as temperature deviates from this point. Far from the nematic temperature, the pitch reaches the nanometer scale and therefore the reflection of visible light. Before crossing zero at the nematic temperature, the optical activity becomes so large that it may be observed with the unaided eye through crossed polarizers.

Original languageEnglish (US)
Pages (from-to)7313-7323
Number of pages11
JournalJournal of the American Chemical Society
Volume125
Issue number24
DOIs
StatePublished - Jun 18 2003

Fingerprint

Liquid Crystals
Enantiomers
Liquid crystals
Polymers
Temperature
Optical Rotation
Light

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

@article{9b5ce76c31df45d0ae05fab2dd2dbe0c,
title = "Chiral conflict. The effect of temperature on the helical sense of a polymer controlled by the competition between structurally different enantiomers: From dilute solution to the lyotropic liquid crystal state",
abstract = "Helical polymers appended with paired structurally different enantiomers, which have opposing helical sense preferences, yield a new kind of relationship between optical activity and temperature, and also reveal unusual details of the nature of chiral interactions. Consistent with a statistical physical theory developed for these experiments, the proportion of the competing chiral groups, determined by synthesis, fixes the compensation temperature at which the helical senses are equally populated. The lyotropic liquid crystal state formed by these polymers yields therefore a nematic state at any chosen temperature over a very wide range, with a cholesteric state arising with tightening pitch as temperature deviates from this point. Far from the nematic temperature, the pitch reaches the nanometer scale and therefore the reflection of visible light. Before crossing zero at the nematic temperature, the optical activity becomes so large that it may be observed with the unaided eye through crossed polarizers.",
author = "Kai Tang and Green, {Mark M.} and Cheon, {Kap Soo} and Selinger, {Jonathan V.} and Bruce Garetz",
year = "2003",
month = "6",
day = "18",
doi = "10.1021/ja030065c",
language = "English (US)",
volume = "125",
pages = "7313--7323",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "24",

}

TY - JOUR

T1 - Chiral conflict. The effect of temperature on the helical sense of a polymer controlled by the competition between structurally different enantiomers

T2 - From dilute solution to the lyotropic liquid crystal state

AU - Tang, Kai

AU - Green, Mark M.

AU - Cheon, Kap Soo

AU - Selinger, Jonathan V.

AU - Garetz, Bruce

PY - 2003/6/18

Y1 - 2003/6/18

N2 - Helical polymers appended with paired structurally different enantiomers, which have opposing helical sense preferences, yield a new kind of relationship between optical activity and temperature, and also reveal unusual details of the nature of chiral interactions. Consistent with a statistical physical theory developed for these experiments, the proportion of the competing chiral groups, determined by synthesis, fixes the compensation temperature at which the helical senses are equally populated. The lyotropic liquid crystal state formed by these polymers yields therefore a nematic state at any chosen temperature over a very wide range, with a cholesteric state arising with tightening pitch as temperature deviates from this point. Far from the nematic temperature, the pitch reaches the nanometer scale and therefore the reflection of visible light. Before crossing zero at the nematic temperature, the optical activity becomes so large that it may be observed with the unaided eye through crossed polarizers.

AB - Helical polymers appended with paired structurally different enantiomers, which have opposing helical sense preferences, yield a new kind of relationship between optical activity and temperature, and also reveal unusual details of the nature of chiral interactions. Consistent with a statistical physical theory developed for these experiments, the proportion of the competing chiral groups, determined by synthesis, fixes the compensation temperature at which the helical senses are equally populated. The lyotropic liquid crystal state formed by these polymers yields therefore a nematic state at any chosen temperature over a very wide range, with a cholesteric state arising with tightening pitch as temperature deviates from this point. Far from the nematic temperature, the pitch reaches the nanometer scale and therefore the reflection of visible light. Before crossing zero at the nematic temperature, the optical activity becomes so large that it may be observed with the unaided eye through crossed polarizers.

UR - http://www.scopus.com/inward/record.url?scp=0038450358&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0038450358&partnerID=8YFLogxK

U2 - 10.1021/ja030065c

DO - 10.1021/ja030065c

M3 - Article

VL - 125

SP - 7313

EP - 7323

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 24

ER -