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Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 30, Number 4
BKCSDE 30(4)
April 20, 2009 

 
Title
Preparation and Unequivocal Identification of Chromophores-Substituted Carbosilane Dendrimers up to 7th Generations
Author
Chungkyun Kim*, Hyojung Kim, Myeong Jin Oh, Jang Hwan Hong
Keywords
Dendrimer, Silane, Siloxane, Photoluminescence, GPC
Abstract
Bis(phenylethynyl)dimethylsilane is branched by the hydrosilation of the phenylethynyl group with dichloromethylsilane, and then the resulting chlorosilane is reacted with lithium phenylacetylide to give the 1st generation. The same hydrosilation and alkynylation are repeated to obtain the 7th generation. In addition peripheral Si-Cl moiety of the seven kind generation dendrimers are reacted with alcoholic moiety of 9-hydroxymethylanthracene and 2-(2-hydroxyphenyl)benzoxazole group in the presence of TMEDA. Then three kinds of carbosilane dendrimers are prepared from the 1st to the 7th generations, the 7th generation of each dendrimer has 256 phenylethynyl, 256 9-anthracenylmethoxy, or 128 2-(2-phenoxy)benzoxazole groups. Each synthesized dendrimer is unequivocally characterized by 1H and 13C NMR, elemental analysis, MALDI-MS, GPC, and PL (photoluminescence). Characteristically PDI (Polydisperse Index) values of the dendrimers’ peak in GPC are in the range of 1.00~1.07, which indicates that each generation of carbosilane is in unified distribution. PL spectra of phenylethynyl and 9- anthracenemethoxy group substituted dendrimers show no significant change with increasing the generation from the 1st to the 7th. However, the PL spectra of 2-(2-phenoxy)benzoxazole group substituted dendrimers show a blue-shift trend with increasing the generation from the 1st to the 7th.
Page
873 - 881
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