http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Chungkyun Kim,Hyojung Kim,Myeong-Jin Oh,Jang-Hwan Hong 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.4
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.
Synthesis of Silafluorene on Dendritic Periphery
Chungkyun Kim*,Wonju Seo,Myeong-Jin Oh 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.11
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.
Conducting Behavior of Carbosilane Dendrimers Including Palladium Ions
Kim, Chungkyun,Koo, Bon-Won,Lee, Sang-Bak,Song, Chung-Kun The Polymer Society of Korea 2002 Macromolecular Research Vol.10 No.3
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.
주행거리에 따른 디스크 브레이크의 마찰 마멸 특성 연구
김청균(Chungkyun Kim),조승현(Seunghyun Cho),한주현(Joohyun Han),강현준(Hyunjoon Kang),김도현(Dohyun Kim),김한구(Hangoo Kim),이일권(Ilkwon Lee) 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.38 No.-
In this paper surface profile, roughness and hardness were experimented for study of friction wear characteristic of automotive disk brake considering running distance. In this work, 5 specimens were employed for roughness test as a function running distance. Despite the fact that brakes must operate under a variety of environmental conditions, most research has worked in laboratory with ideal condition. This paper investigated the average roughness of disk brakes which are actually operated in automotive. Average roughness decreased with running distance from 0 to about 10,000㎞ due to unevenly contact surfaces between disk brake and pads. But that has been increased with running distance from about 10,000 to 20,000㎞ due to loss of solid lubrication film and higher contact pressure between two rubbing surfaces.
Synthesis of Terpyridine Dendrimer
Kim, Chungkyun,Kim, Hyojeong 동아대학교 기초과학연구소 2003 基礎科學硏究論文集 Vol.20 No.1
Dendrimers with 2,2':6,2˝-terpyridine groups on the periphery were prepared by chlorinated parent dendrimers (Gn-mCl; n = 1, m = 4; n = 2, m = 8; n = 3, m = 16) and 6-hydroxy-1-oxyhexa-4'-(2,2':6'.2˝-terpyridine). Dendrimers have been characterized by NMR, UV, MALDI Mass and elemental analysis.
Silane Arborols; XV:¹A Dendritic Carbosilane Based on Siloxane Tetramers
Kim, Chungkyun,Kwon, Aejeong 東亞大學校附設基礎科學硏究所 1998 基礎科學硏究論文集 Vol.15 No.1
An improved synthesis of the spherical dendritic macromolecule G2 with 36 allylic end groups starting from allyl alcohol and trichlorosilane as the building blocks and siloxane tetramers as core molecules is described. The formation of pure and uniform dendrimers was controlled by ¹H and ??? NMR spectra. MALDI mass spectra, and elemental analyses. The subsequent generation of G3P with 108 Si-Cl bonds starting from G2 could not be made uniform by repetition of key intermediate steps.
Kim, Chungkyun,An, Kyungmi 東亞大學校附設基礎科學硏究所 1998 基礎科學硏究論文集 Vol.15 No.1
Starting with 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-2,4,6,8-tetrasila-1,3,5,7-tetraoxacyclooctane (Me(CH₂=CH)SiO)₄ as a core molecule, a succession of alternate platinum-catalyzed hydrosilations of all vinyl groups with HSiMeCl₂, as well as alkenylation with allylmagnesium bromide, provided the third generation (G3) as divergent growth of siloxane-based dendrimers. The reaction path of the repetitive allylation/hydrosilation cycles is controlled with NMR spectroscopic analyses. Each of the two steps provided quantitative yields of pure dendrimers. We also changed the simple construction of the G3P molecule into materials with special functions, such as by adding phenylethynyl and p-bromophenoxy groups on its periphery. ⓒ1997 Elsevier Science S.A.
Thermal Decomposition Evidence of Silylated Pyridine Derivatives
Kim,ChungKyun,Park,Eunmi,Choi, Soon-Kyu 東亞大學校附設基礎科學硏究所 1995 基礎科學硏究論文集 Vol.12 No.1
Thermal decomposition reaction of 2-methylenlsilyl- and 2-bis(trimethylsilyl) methylpyridine derivatives (2-4) with methanol imidazole and bromoform are progressed to collidine(1) and related thermolysis products(5-8). Decomposition rate of given compounds should be followed acidity of reactants.
Kim, Chungkyun,Kwon, Aejeong 東亞大學校附設基礎科學硏究所 1998 基礎科學硏究論文集 Vol.15 No.1
Starting with allyl groups containing polycarbosilane as a core molecule, a succession of alternate platinum catalyzed hydrosilations of all allyl groups with HSiMeCl₂ as well as alkenylations with allylmagnesium bromide provided polycarbosilane-based dendrimers. The polymeric carbosilane dendrimer provided the materials with specific functions of intriguing supramolecular phenomena with phenylethynl, p-bromophenoxy, and p-phenylphenoxy groups.
SYNTHESIS AND TERMINATION OF CARBOSILANE DENDRIMERS
Kim, Chungkyun,Kang, Sungkyung 東亞大學校附設基礎科學硏究所 1998 基礎科學硏究論文集 Vol.15 No.2
48개의 SiMe₂H기능기를 가진 카아르보실란 나뭇가지꼴 거대분자를 합성하였다. 하이드로실레이숀과 알캔일레이숀의 반복적인 과정을 경유하여 제3세대(G3)까지의 합성과정을 NMR에 의해서 확인하였다. G3와 Me₂SiHCl의 반응에 의해서 G4P-1Cl이 형성 되었고 이것은 다시 LAH에 의해서 G4P-1H를 형성하였다. 하이드로실레이숀과 알캔일레이숀의 반복적인 과정을 경유하여 형성된 이 화합물은 모두 정량적인 수율과 높은 순도를 제공하였다. Dendritic carbosilane with 48 SiMe₂H groups have been prepared. The reaction path of the repetitive hydrosilation-alkenylation cycles to G3 is revealed by NMR spectroscopy. The G3 with dimethylchlorosilane produced G4P-1Cl and than produced G4P-1H by the reaction of LAH. Each of the two steps proved quantitative yield of pure dendrimer.