• 통합자연과학논문집
• /
• 제3권2호
• /
• pp.61-71
• /
• 2010

Hydrosilanes possessing reactive Si-H bond are used in synthesizing various types of polysilanes by dehydrocoupling under the influence of various organometallic promoters. Catalytic Si-Si/Si-O coupling of hydrosilanes with hydrosilanes, alcohols, and lactones to silicon-based polymers are described in this article as selective examples of our recent research developments. These silicon-containing polymers can be used as a precursor to prepare useful functional materials for fabricating electronic devices.

• Bulletin of the Korean Chemical Society
• /
• 제22권12호
• /
• pp.1337-1340
• /
• 2001

The bulk photopolymerization of methyl methacrylate (MMA) with para-substituted phenylsilanes such as F-C6H4SiH3 (1), H3C-C6H4SiH3 (2), and H3CO-C6H4SiH3 (3) was performed to produce poly(MMA)s containing the respective silyl moiety as an end group. For all the hydrosilanes, the polymerization yields and the polymer molecular weights decreased, whereas the TGA residue yields and the relative intensities of Si-H IR stretching bands increased as the relative silane concentration over MMA increased. The polymerization yields and polymer molecular weights of MMA with 1-3 increased in the order of 3 < 1 < 2. These hydrosilanes influence significantly upon the photopolymerization of MMA as both chain-initiation and chain-transfer agents.

• 통합자연과학논문집
• /
• 제2권1호
• /
• pp.18-23
• /
• 2009

This minireview provides the chosen examples of our recent discoveries in the polymerization of hydrosilanes, dihydrosilole, lactones, and vinyl derivatives using various catalysts. Hydrosilanes and lactones copolymerize to give poly(lactone-co-silane)s with $Cp_2MCl_2$/Red-Al (M = Ti, Zr, Hf) catalyst. Hydrosilanes (including dihydrosilole) reduce noble metal complexes (e.g., $AgNO_3$, $Ag_2SO_4$, $HAuCl_4$, $H_2PtCl_6$) to give nanoparticles along with silicon polymers such as polysilanes, polysilole, polysiloxanes (and silicas) depending on the reaction conditions. Interestingly, phenylsilane dehydrocoupled to polyphenylsilane in the inert nitrogen atmosphere while phenylsilane dehydrocoupled to silica in the ambient air atmosphere. $Cp_2M/CX_4$ (M = Fe, Co, Ni; X = Cl, Br, I) combination initiate the polymerization of vinyl monomers. In the photopolymerization of vinyl monomers using $Cp_2M/CCl_4$ (M = Fe, Co, Ni), the photopolymerization of MMA initiated by $Cp_2M/CCl_4$ (M = Fe, Co, Ni) shows while the polymerization yield decreases in the order $Cp_2Fe$ > $Cp_2Ni$ > $Cp_2Co$, the molecular weight decreases in the order $Cp_2Co$ > $Cp_2Ni$ > $Cp_2Fe$. For the photohomopolymerization and photocopolymerization of MA and AA, the similar trends were observed. The photopolymerizations are not living. Many exciting possibilities remain to be examined and some of them are demonstrated in the body of the minireview.

• 한국안광학회지
• /
• 제5권2호
• /
• pp.87-90
• /
• 2000

Poly(HEMA)는 소프트 콘택트렌즈의 재료로써 널리 사용되어 왔다. $phSiH_3$, $phMeSiH_2$, $ph2SiH_2$와 같은 다양한 hydrosilane들과 hydroxyethyl methacrylate(HEMA)와의 열중합은 Phenylsilyl 말단기를 포함하는 poly(HEMA)를 생성시켰다. 열중합 반응 동안에는 Phenylsilane의 농도가 증가함에 따라 고분자의 분자량과 고분자 수득률이 감소됨을 보였으며 광중합 반응에서 보다 중합 수득률, 고분자의 분자량, TGA 잔여 수율 등이 더 높았다.

• Bulletin of the Korean Chemical Society
• /
• 제18권2호
• /
• pp.164-170
• /
• 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.

• Bulletin of the Korean Chemical Society
• /
• 제15권12호
• /
• pp.1103-1107
• /
• 1994

Interaction of triethylsilane and diphenylsilane ($Ph_2$$SiH_2$, $Ph_2$$SiD_2$) with the surfaces of rhodium has been examined by trapping the reaction intermediates with 2,3-dimethyl-l,3-butadiene. 1,4-Hydrosilylation of the diene is predominantly observed to occur under mild condition over the rhodium catalyst. It is inferred from the product analyses that silylene and silyl radicals bonded to rhodium surfaces are the intermediates for addition of silylene to the diene, and for 1,4-hydrosilylation, respectively.

• 통합자연과학논문집
• /
• 제2권4호
• /
• pp.289-292
• /
• 2009

Perchlorosilanes are useful precursors for the synthesis of hydrosilanes for the fabrication of electronic devices such as silicon thin-film transistors and silicon nanoparticles. For this solution process, requirements of precursors applicable to solution process are relatively low volatile and soluble in common organic solvents. In this work, the decaphenylcyclopentasilane has been obtained from the reaction of the lithium wire and dichlorodiphenylsilane. The reaction of decaphenylcyclopentasilane with lewis acid catalyst, HCl/$AlCl_3$, gives the perchlorocyclopentasilane. Decaphenylcyclopentasilane exhibits an unusual optical property. Its optical property was characterized by UV-vis and fluorescence spectroscopy. Absorption wavelength maxima for the decaphenylcyclopentasilane was 272 nm. Decaphenylcyclopentasilane displayed an emission band at 741 nm with excitation wavelength of 272 nm.

• 통합자연과학논문집
• /
• 제2권1호
• /
• pp.1-12
• /
• 2009

This miniaccount presents the selective examples of our recent discoveries in the photopolymerization of vinyl monomers using the organic initiators such as hydrosilanes, poly(hydroarylsilane)s, benzoin silyl ethers, and thianthrene cation radical. In the photopolymerization of vinyl monomers with silanes polysilanes, while the polymerization yields and polymer molecular weights of the poly(MMA)s containing the silyl moieties decreased, the TGA residue yields and intensities of SiH stretching IR bands increased as the mole ratio of the silanes over MMA increased. The hydroarylsilane and poly(hydroarylsilane) seemed to influence strongly on the photopolymerizaiton of olefinic monomers as both chain initiation and chain transfer agents. For the photohomopolymerization and photocopolymerization of MA and AA, the similar trends were observed. Benzoin silyl ethers and thianthrene cation radical also exhibit the photoinitiating ability in the photopolymerization of MMA.

• 한국안광학회지
• /
• 제8권2호
• /
• pp.129-134
• /
• 2003

불포화 비닐 유도체의 다양한 반응성은 자유 라디칼의 사슬 중합반응을 거쳐 유도되어질 수 있으며, 열역학적으로 실행 가능한 고분자 중합을 수행할 수 있는 능력은 주어진 반응조건 항서 반응을 진행시킬 수 있는 적당한 속도에 의존한다. 따라서 반응이 일어날 수 있는 속도조건을 만들기 위해 중합 개시제와 촉진제가 주로 사용되고 있다. 빛의 흡수도는 Methyl Methacrylate(MMA)를 포함한 단지 몇 종류의 불포화 비닐 단량체들만이 가장 편리한 250nm~500nm 파장범위의 빛을 흡수할 수 있다고 알려져 있다. 또한 광학적, 전기적으로 독특한 성질을 가진 polysilanes은 세라믹의 전구물질, UV 광전저항, 광전도체 등으로 널리 사용되어 왔으며, hydrosilation 반응은 실리콘을 포함한 여러 가지 흥미로운 고분자를 만드는데 사용되고 있다 본 연구는 콘텍트렌즈 재료로 사용되는 고분자를 광 화학적 개시제의 작용을 통하여 공중합체와 단일 중합체로 합성하여 그 수율을 분석하였다. 그 결과 이러한 개시제들은 비닐 유도체들의 중하반응에서 경쟁적으로 또는 동시에 사슬 개시와 사슬 전이제로서 작용하고 있음을 보여 주었다.