Chiral Alignment of OPV Chromophores: Exploitation of the Ureidophthalimide-Based Foldamer

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• 作者：Renatus W. Sinkeldam ; Freek J. M. Hoeben ; Maarten J. Pouderoijen ; Inge De Cat ; Jian Zhang ; Shuhei Furukawa ; Steven De Feyter ; Jef A. J. M. Vekemans ; E. W. Meijer
• 刊名：Journal of the American Chemical Society
• 出版年：2006
• 出版时间：December 20, 2006
• 年：2006
• 卷：128
• 期：50
• 页码：16113 - 16121
• 全文大小：3887K
• 年卷期：v.128,no.50(December 20, 2006)
• ISSN：1520-5126

文摘

The ability of foldamers to adopt a secondary structure in solution has been exploited to organizeperipheral functionality. Our previously reported poly(ureidophthalimide) foldamer proved to be an excellentscaffold for the chiral organization of peripherally positioned oligo(p-phenylenevinylene) (OPV) chromophores. Facile high-yielding synthesis gave access to the required OPV-decorated building blocks. Acondensation polymerization provided polymers of sufficient length to allow construction of a helicalarchitecture comprising several turns. Short and long chains were separated by chromatography. Circulardichroism studies in THF of the longer chains indicate the presence of helically arranged OPVs. However,such an effect is not observed in CHCl₃. Remarkable are the measurements of the OPV foldamers inheptane. A bisignate Cotton effect is observed in heptane of a sample with a THF history. No Cotton effectis observed in heptane of a sample with a CHCl₃ history. In this example of supramolecular synthesis, thesolvent dictates the expression of supramolecular chirality in a secondary structure. The short-chainoligomeric fractions that are unable to create a full turn revealed on scanning tunneling microscopy analysisthe presence of circular architectures at the graphite/1-phenyloctane interface. This is in full agreementwith the proposed conformation of the decorated foldamers.