Foldamer Organogels: A Circular Dichroism Study of Glucose-Mediated Dynamic Helicity Induction and Amplification
This paper reports a systematic study of the dynamic process for the self-assembly of chiral organogels from achiral hydrogen bonded hydrazide foldamers by induction of chiral glucose. Six foldamers incorporated with six decyl chains and two benzene, naphthalene, anthracene, or pyrene units at the e...
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Published in | Journal of the American Chemical Society Vol. 130; no. 40; pp. 13450 - 13459 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
08.10.2008
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | This paper reports a systematic study of the dynamic process for the self-assembly of chiral organogels from achiral hydrogen bonded hydrazide foldamers by induction of chiral glucose. Six foldamers incorporated with six decyl chains and two benzene, naphthalene, anthracene, or pyrene units at the ends are revealed to strongly gelate apolar and polar solvents, including alkanes, arenes, esters, alcohols, and 1,4-dioxane. The gels are characterized by UV−vis, fluorescent, XRD, SEM, and AFM methods, based on which a dislocated “tail-to-tail” stacking pattern is proposed. Addition of octylated glucose considerably enhances the capacity of the foldamers to gelate apolar solvents due to strong complexation. The complexation also causes unique dynamic helicity induction in the gels, which is studied systematically by circular dichroism. The results are treated with the Avrami theory according to a reported method (J. Am. Chem. Soc. 2005, 127, 4336), which suggests that the gelation involves a nucleation−elongation mechanism. In addition, the “Sergeants and Soldiers” effect in the gel phase is also revealed. |
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Bibliography: | istex:236FD97C559A7F68CB031B513048B04EFF58FB32 Experimental procedures and characterizations, 1H NMR of 1a−f and 2, and additional UV−vis, fluorescent, CD, and XRD spectra and SEM and AFM images. This material is available free of charge via the Internet at http://pubs.acs.org. ark:/67375/TPS-8RHMVR04-B ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0002-7863 1520-5126 |
DOI: | 10.1021/ja8043322 |