کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5183584 | 1381023 | 2012 | 8 صفحه PDF | دانلود رایگان |
Novel poly(m-phenyleneethynlene-p-phenyleneethynylene)s bearing polymerizable diene or norbornene groups were synthesized by the Sonogashira-Hagihara coupling polymerization of the corresponding d-hydroxyphenylglycine-derived diiodo monomers with p-diethynylbenzene. These polymers exhibited strong Cotton effects derived from a predominantly one-handed helical conformation in CHCl3 and tetrahydrofuran, but exhibited weak or no Cotton effects in N,N-dimethylformamide. The metathesis polymerization of the diene and norbornene moieties was performed at the side chains of the polymers under diluted conditions in the presence of a chain-transfer agent, if necessary. The reaction took place intramolecularly, which was confirmed by size exclusion chromatography (SEC) measurements. The polymers exhibited stronger Cotton effects even in polar media after the intramolecular crosslinking, which indicated stabilization of the predominantly one-handed helical structures.
Journal: Polymer - Volume 53, Issue 13, 7 June 2012, Pages 2559-2566