Document Detail

Temperature-induced chiroptical changes in a helical poly(phenylacetylene) bearing N,N-diisopropylaminomethyl groups with chiral acids in water.
MedLine Citation:
PMID:  17763496     Owner:  NLM     Status:  MEDLINE    
A stereoregular poly(phenylacetylene) bearing an N,N-diisopropylaminomethyl group as the pendant (poly-1) changed its structure into the prevailing one-handed helical conformation upon complexation with optically active acids in water. The complexes exhibited induced circular dichroism (ICD) in the UV/Vis region of the polymer backbone. Poly-1 is highly sensitive to the chirality of chiral acids and can detect a small enantiomeric imbalance in these acids, in particular, phenyl lactic acid in water. For example, a 0.005% enantiomeric excess of phenyl lactic acid can be detected by CD spectroscopy. The observed ICD intensity and pattern of poly-1 were dependent on the temperature and concentration of poly-1, probably due to aggregations of the polymer at high temperature as revealed by dynamic light scattering and AFM. On the basis of the temperature-dependent ICD changes, the preferred chiral helical sense of poly-1 was found to be controlled by noncovalent bonding interactions by using structurally different enantiomeric acids.
Kanji Nagai; Katsuhiro Maeda; Yoshihisa Takeyama; Takahiro Sato; Eiji Yashima
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Chemistry, an Asian journal     Volume:  2     ISSN:  1861-471X     ISO Abbreviation:  -     Publication Date:  2007 Oct 
Date Detail:
Created Date:  2007-10-01     Completed Date:  2007-11-08     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101294643     Medline TA:  Chem Asian J     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  1314-21     Citation Subset:  IM    
Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan.
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MeSH Terms
Acetylene / analogs & derivatives*,  chemistry
Carboxylic Acids / chemistry*
Circular Dichroism
Molecular Conformation
Sulfonic Acids / chemistry*
Water / chemistry
Reg. No./Substance:
0/Carboxylic Acids; 0/Sulfonic Acids; 0/poly(phenylacetylene); 74-86-2/Acetylene; 7732-18-5/Water

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