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Synthesis of Polyisoprene Terpenoid Dendrons and their Applications in Oligo(phenylene ethynylene)s as “Shells”

✍ Scribed by Wen-Yu Chai; Dr. Zi-Fa Shi; Peng An; Wei Wang; Lu-Feng Wang; Prof. Xiao-Ping Cao


Publisher
John Wiley and Sons
Year
2011
Tongue
English
Weight
433 KB
Volume
7
Category
Article
ISSN
1861-4728

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✦ Synopsis


Abstract

The novel double‐stage convergent synthesis of a new class of polyisoprene terpenoid (PIPTP) dendrons is described. PIPTP dendrons bear a highly branched aliphatic hydrocarbon skeleton and a hydrophilic hydroxy focal point functionality. These dendrons have the specific formula C~(5×2~^G+1^~‐5)~H~(5×2~^G+2^~‐8)~O, and each dendritic layer is constructed from an isoprene unit. The key branching steps involve a double alkyl‐metal addition to an ester functionality, followed by deoxygenation of the resulting tertiary alcohol by triethylsilane and trifluoroacetic acid, then hydrogenation or hydrogenolysis. The dendrons were also attached to oligo(phenylene ethynylene)s (OPEs) so as to function as protective shells to allow fine tuning of the nanoscopic environment around the OPE moiety, and to exert precise control of the packing density and intermolecular interaction between the OPE cores. Fluorescence quantum yield data reveal that the OPE core is better encapsulated by the PIPTP dendrons than by Fréchet dendrons.