• Title/Summary/Keyword: Carbosilane

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The Formation of Dendrimeric Silane on Poly(carbosilane): Silane Arborols $(V)^1$ (Carbosilane 고분자상의 나무가지꼴 실란거대분자 형성: Silane Arborols $(V)^1$)

  • Kim, Chung Kyun;Park, Eun Mi;Jung, In Kyung
    • Journal of the Korean Chemical Society
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    • v.40 no.5
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    • pp.347-356
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    • 1996
  • The selective cleavage of phenylsilane by triflic acid gives silyltriflates. The removal of phenyl groups in $Ph_3SiH$ and carbosilane polymer $(Ph_2SiCH_2CH_2CH_2)n$ with one to two equiv of triflic acid leads to formation of mono- and disubstituted silyltriflate ester bonds. Reaction with allylmagnesium bromide produces corresponding derivatives with good yields. An organosilane dendrimer with allylated carbosilane polymer has been synthesized up to G3 using repetitive allylation hydrosilylation cycles.

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Synthesis and Characterization of A Carbosilane Dendrimer Containing Allylic End Groups

  • 김정균;박은미;강은주
    • Bulletin of the Korean Chemical Society
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    • v.17 no.7
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    • pp.592-595
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    • 1996
  • A silane dendrimer with 48 allylic end groups has been synthesized in excellent yield, via repetitive alkenylation-hydrosilation cycles. Starting with hexaallylethylenedisilane ((CH2=CHCH2)3SiCH2)2 as the core molecule (G0), a succession of alternate platinum catalyzed hydrosilation (Pt/C, 10% platinum content on active carbon) of all allyl groups with methyldichlorosilane and the allylation of all SiCl2 groups with allylmagnesium bromide in THF provided 3rd generation (G3) as carbosilane dendrimer. All the generations of dendrimer have been characterized by 1H and 13C NMR spectroscopy as well as elemental analysis.

Preparation of Carbosilane Dendrimers Based on Siloxane Tetramer: Silane Arborols $(VII)^1$

  • 김정균;안경미
    • Bulletin of the Korean Chemical Society
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    • v.18 no.2
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    • pp.164-170
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    • 1997
  • Via hydrosilation-alkenylation approach using hydrosilanes (HSiMeCl2 and HSiCl3) and allylmagnesium bromide with siloxane tetramer (MeCH2=CHSiO)4 as core molecule, noble carbosilane dendrimers with 12, 24, 48 and 96 allylic end groups have been prepared. The reaction path of the repetitive alkenylation and hydrosilation was monitored by means of NMR spectroscopic measurements. Every step for the formation of dendrimer provided almost quantitative yields as pure dendrimers. Based on the observation of UV spectroscopic measurements of Gn (n=1-4) molecules containing allylic end groups, the maximal molal absorption coefficients (εmax) at λmax and the number of double bonds proved an exponentially increased correlation.

SiOC Anode Material Derived from Poly(phenyl carbosilane) for Lithium Ion Batteries

  • Lee, Yoon Joo;Ryu, Ji Yeon;Roh, Kwang Chul;Kim, Soo Ryong;Kwon, Woo Teck;Shin, Dong-Geun;Kim, Younghee
    • Journal of the Korean Ceramic Society
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    • v.50 no.6
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    • pp.480-484
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    • 2013
  • Since SiOC was introduced as an anode material for lithium ion batteries, it has been studied with different chemical compositions and microstructures using various silicon based inorganic polymers. Poly(phenyl carbosilane) is a SiOC precursor with a high carbon supply in the form of the phenyl unit, and it has been investigated for film applications. Unlike any other siloxane-based polymers, oxygen atoms must be utilized in an oxidation process, and the amount of oxygen is controllable. In this study, SiOC anodes were prepared using poly(phenyl carbosilane) with different heat treatment conditions, and their electrochemical properties as an anode material for lithium ion batteries were studied. In detail, cyclic voltammetry and charge-discharge cycling behavior were evaluated using a half-cell. A SiOC anode which was prepared under a heat treatment condition at $1200^{\circ}C$ after an oxidation step showed stable cyclic performance with a reversible capacity of 360 mAh/g.

Conducting Behavior of Carbosilane Dendrimers Including Palladium Ions

  • Kim, Chungkyun;Koo, Bon-Won;Lee, Sang-Bak;Song, Chung-Kun
    • Macromolecular Research
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    • v.10 no.3
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    • pp.178-180
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    • 2002
  • The conducting behavior of dendritic carbosilanes including palladium ions (Pd$^{2+}$) has been measured. The palladium ion containing dendrimers were prepared by the addition of palladium dichloride to double-layered dendritic carbosilanes, which consist of phenylethynyl groups (-C≡CPh) on the outmost periphery as well as phenylethenyl and propyleneoxy groups (-CH=CPh- and (CH$_2$)$_3$O-) in the inner shell. By measuring conductivities, palladium ion containing dendrimers revealed an increasing tendency according to the increasing number of double bonds in the inner shells of dendritic carbosilanes.s.

Synthesis of Silafluorene on Dendritic Periphery

  • Kim, Chung-Kyun;Seo, Won-Ju;Oh, Myeong-Jin
    • Bulletin of the Korean Chemical Society
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    • v.28 no.11
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    • pp.1963-1966
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    • 2007
  • Carbosilane dendrimers with silafluorenyl groups on the periphery were prepared by the reaction of 2,2'- dilithiumbiphenyl and dichlorosilyl groups on the carbosilane dendrimers at low temperature. The 1st to 4th generation of dendrimers with silafluorenyl groups were obtained with high yields and the products were purified by column chromatography. The unified properties of the dendrimers were measured by gel permeation chromatography (GPC) and displayed very low and regular polydispersity index (PDI) value. The silafluorenyl moieties on dendritic periphery accepted the potassium fluoride ions which were stabilized by criptand [222], and it proved strong photoluminescent properties.

Preparation and Unequivocal Identification of Chromophores-Substituted Carbosilane Dendrimers up to 7th Generations

  • Kim, Chung-Kyun;Kim, Hyo-Jung;Oh, Myeong-Jin;Hong, Jang-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.30 no.4
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    • pp.873-881
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    • 2009
  • 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 $1^{st}$ generation. The same hydrosilation and alkynylation are repeated to obtain the $7^{th}$ 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 $1^{st}$ to the $7^{th}$ generations, the $7^{th}$ generation of each dendrimer has 256 phenylethynyl, 256 9-anthracenylmethoxy, or 128 2-(2-phenoxy)benzoxazole groups. Each synthesized dendrimer is unequivocally characterized by $^1H\;and\;^{13}C\;NMR$, elemental analysis, MALDI-MS, GPC, and PL (photoluminescence). Characteristically PDI (Polydisperse Index) values of the dendrimers’ peak in GPC are in the range of $1.00{\sim}1.07$, 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 $1^{st}$ to the $7^{th}$. However, the PL spectra of 2-(2-phenoxy)benzoxazole group substituted dendrimers show a blue-shift trend with increasing the generation from the $1^{st}$ to the $7^{th}$.