Study on the Conformation of Poly(aryl ether) Dendrimers by Fluorescence Quenching

doi:10.7517/j.issn.1674-0475.2016.02.144

Abstract

Abstract:

Two series of poly(aryl ether) dendrimers with only one pyrene chromophore attached to the periphery (Py-Gn-OH) orto the focal point (Gn-CH₂-Py)were synthesized. Fluorescence emission and fluorescence lifetime of Py-Gn-OH and Gn-CH₂-Py increase with increasing the generation.Fluorescence quenching experiments demonstrate that the bimolecular quenching rate constant k_qof Py-Gn-OH and Gn-CH₂-Py decreases as the generation increases, indicating that the poly(aryl ether) dendrimers possess a folding back conformation. The pyrene chromophore located either at the periphery or at the core is encapsulated by the dendritic backbone. The extent of encapsulation increases with the generation, giving an increased shield effect from the encounter with solvent and quencher molecules. The k_q value of Gn-CH₂-Py is slightly smaller than those of the corresponding generation of Py-Gn-OH, indicating that the dendritic backbone exhibits a better extent of encapsulation for the chromophore at core than that at the periphery. This study provides a reference for designand application of novel functional dendrimers.

Key words: poly(aryl ether) dendrimer, conformation, pyrene, fluorescence quenching

LI Yingying, LI Yi. Study on the Conformation of Poly(aryl ether) Dendrimers by Fluorescence Quenching[J]. Imaging Science and Photochemistry, 2016, 34(2): 144-151.

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