• 생명과학회지
• /
• 제8권6호
• /
• pp.673-680
• /
• 1998

Nocardioides sp. J-326TK의 adenosine deaminase gene을 분리하기 위하여 genomic DNA를 제한효소로 무작위적으로 절단하여 pBluscript KS에 ligation시켰다. 또한 hu-man과 mouse, E. cali 등의 adenosine deaminase gene의 보존적인 부위를 primer로 합성을 하여 PCR reaction을 행하였다. Genomic DNA를 cloning시킨 pKSN60은 5kb정도의 DNA를 포함하고 있으며 sourthern hybridization 등의 여러 확인 실험을 통하여 adenosine deaminase gene을 포함하고 있다는 알았다. PCR product를 cloning시켜 형성된 recombinant plasmid를 PCR reaction의 primer로서 pTBN20를 sequencing을 행하였다. 그 결과를 다른 ade-nosine deaminase gene의 서열과 비교를 하였는데 미생물인 E. coli와는 nucleotide sequence는 99.5%, amino acid sequence는 98.9%의 homology를 나타내고 human과는 각각 59.5%, 46.8%의 homolosy를 나타내었다.

• Bulletin of the Korean Chemical Society
• /
• 제34권11호
• /
• pp.3350-3356
• /
• 2013

Quasi-classical trajectory calculations have been carried out for the reaction H+HS by using the newest triplet 3A" potential energy surface (PES). The effects of the collision energy and reagent initial rotational excitation are studied. The cross sections and thermal rate constants for the title reaction are calculated. The results indicate that the integral cross sections (ICSs) are sensitive to the collision energy and almost independent to the initial rotational states. The ro-vibrational distributions for the product $H_2$ at different collision energies are presented. The investigations on the vector correlations are also performed. It is found that the collision energies play a postive role on the forward scatter of the product molecules. There is a negative influence on both the alignment and orientation of the product angular momentum for low collision energy at low energy region. Whereas the influence of collision energy is not obvious at high energy region.

• Bulletin of the Korean Chemical Society
• /
• 제33권12호
• /
• pp.4117-4121
• /
• 2012

The solvolysis rate constants of allyl chloroformate ($CH_2=CHCH_2OCOCl$, 3) in 30 different solvents are well correlated with the extended Grunwald-Winstein equation, using the $N_T$ solvent nucleophilicity scale and $Y_{Cl}$ solvent ionizing scale, with the sensitivity values of $0.93{\pm}0.05$ and $0.41{\pm}0.02$ for l and m, respectively. These l and m values can be considered to support a $S_N2$ reaction pathway. The activation enthalpies (${\Delta}H^{\neq}$) were 12.5 to 13.4 $kcal{\cdot}mol^{-1}$ and the activation entropies (${\Delta}S^{\neq}$) were -34.4 to -37.3 $cal{\cdot}mol^{-1}{\cdot}K^{-1}$, which is also consistent with the proposed bimolecular reaction mechanism. The solvent kinetic isotope effect (SKIE, $k_{MeOH}/k_{MeOD}$) of 2.16 was also in accord with the $S_N2$ mechanism. The values of product selectivity (S) for the solvolyses of 3 in alcohol/water mixtures was 1.3 to 3.9, which is also consistent with the proposed bimolecular reaction mechanism.

• Bulletin of the Korean Chemical Society
• /
• 제21권7호
• /
• pp.715-719
• /
• 2000

A ceramic powder of destructive adsorbent was synthesized by impregnating copper and manganese on the surface of silica aerosil@. In-site FTIR measurements on pulses of malodorant tert-butylmercaptan injected over the powder showed that rert-butylmercaptan dimerized into di-tert-hutyldisulfide on the surface of the adsorbent in an ambient condition. GC/MS measurement on the gas over the adsorbent showed no tert-butylmercaptan remaining, and showed only the dimerization product of di-tert-butyldisulfide. Most of the dimerization product, di-tert-butyldisulfide,remained on the surface of the adsorbent as physisorbed condense, and apparently Iowered the destruction efficiency by blocking the surface from the access by tert-butylmercaptan. Upon being heated above $100^{\circ}C$ it was observed that the physisorbed di-tert-butyldisulfide dissociated back into tert-butylmercaptan. tert-butylmercaptan physisorbed on the activated carbon, thereby no dimerization was occurring on the surface of the activated carbon. In an argn environment, the dimerization reaction was practically not occurring even on the surface of the adsorbent, indicating the free oxygen in air was also participating in the dimerization reaction. Water was identified as a by-product of the dimerization reaction. Possible reactions on the surface of the adsorbent were proposed.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2019년도 추계학술대회
• /
• pp.267-267
• /
• 2019

위험물 운반선에 적재된 물질에 화재나 폭발사고와 같은 선박사고가 발생하는 경우, 그 경로가 매우 복잡하기 때문에 사고의 원인을 추정하기가 어렵다. 이는 사고를 일으킨 원인에 대한 증거가 없거나, 선박 안에서 어떤 화학반응이 일어났는지를 시각적으로 파악하기 힘들기 때문이다. 본 연구에서는 폭발사고를 야기시키는 화학물질에 화학반응식을 도입한 사건가지분석(Event Tree Analysis, ETA)기법을 적용하여 선박에 적재된 화학물의 화재사고 경로를 추정하는 연구를 하였다. 그 결과 다양한 화학반응식을 나타낼 수 있었으며, 그것을 ETA기법에 적용하여 폭발경로를 보다 시각화 할 수 있었다.

• 대한화학회지
• /
• 제36권1호
• /
• pp.81-86
• /
• 1992

M(S-S,ph)(N-N,H) (M = Ni(II), Pd(II), Pt(II); (S-S,ph) = 1,2-diphenylethylenedithiolate; (N-N,H)=1,10-phenanthroline) 착물의 친전자성 및 친핵성 리간드 반응을 조사하였다. norbornadiene과의 반응성은 중심금속의 역결합의 정도에 의존하며 2,5-dithia-3,4-diphenyl-tricyclo[4,4,1,0]-undeca-3,8-diene을 생성하였다. methyl iodide와의 반응은 (N-N,H) 리간드의 이탈 능력에 지배되며 메틸화된 $M(S-S,ph)_2$ 착물을 생성하였다. 이 반응의 주생성무리은 열 분해에 의해 얻어진 ${\alpha},{\alpha}{\prime}$,-bismethylthiostibene $(CH_3S-SCH_3,ph)$의 구조로부터 M(S-S,CN)(N-N,H)((S-S,CN) = 1,2-dicyanoethylenedithiolate)의 새로운 혼합 리간드 착물을 합성하였다.

• 대한화학회지
• /
• 제9권1호
• /
• pp.1-7
• /
• 1965

토루엔, 디메틸폴움아마이드, 디메틸슬포옥사이드, 테트라하이드로퓨란, 아세토나이트라일 및 디옥센 等 溶媒存在下에서 모노클로로醋酸과 亞鉛을 反應시켜 본 結果, 溶媒효果를 나타내었다. 反應試藥의 反應度가 溶媒의 極性 및 親水性에 따라 增加하였다. 같은 溶媒系를 使用하여 에틸모노클로로醋酸을 反應시켜 본 結果, 溶媒효果를 나타냈으나 酸의 境遇보다 그 差가 크지 못하였다. 酸, 에스타, 亞鉛 및 카보닐化合物(벤즈알데히드 및 4-헤프타논)의 反應에 있어서는 알데하이드의 境遇에 있어서는 Reformatsky 反應生成物을 주었으나, 4-헤프타논과의 反應度는 없었다. 反應生成物의 收率은 試藥添加方法에 따라 變化되었다. 最高收率은 酸의 하이드로옥시酸(38.5%), 0.8g의 salt(아세트나이트라일溶媒)이며, 에스타의 境遇에는 에틸신나메이트(19.3%), 폴리머(21.6%)이였다. 카보닐化合物의 境遇에 있어서는 反應溫度에 따라 試藥의 反應度의 變化가 있었다. 硏究結果를 溶媒效果에 關聯시켜 論議하였으며, 硏究方法에 關하여 記述하였다.

• 한국세라믹학회지
• /
• 제43권4호
• /
• pp.207-212
• /
• 2006

[ ${\varepsilon}-caprolactam$ ] was polymerized in the layers of the [DEACOOH]-Montmorillonite intercalations complex at high temperatures ranging from 250% to 260% formed from Na-Montmorillonite and 10-Carboxy-n-decyldimethylethylammonium bromide to achieve [DEACOOH]-Polycaprolactam-Montmorillonite, in which an inorganic polymer (montmorillonite) is chemically combined with an organic polymer (polycaprolactam). The results of X-ray and IR analyses for the samples obtained after polymerization showed that the polymerization reaction was successfully accomplished. For the purpose of studying the polymeric reaction product more precisely, the polymerized product was separated from the silicate layers and analyzed with an X-ray diffractometer and an IR-spectrometer. A comparison of the results of the X-ray and IR analyses of the separated polymer and the polymer that was synthesized by the reaction of ${\varepsilon}-caprolactam$ solely with the organic cation without montmorillonite showed that the obtained both polymers are identical compounds.

• Bulletin of the Korean Chemical Society
• /
• 제28권9호
• /
• pp.1515-1518
• /
• 2007

A preparative method of Me2SCuX (X = Cl, Br) via one-pot reaction was developed from common chemicals such as benzyl halide, DMSO, and Cu(0). In the reaction mixture small molecules such as methyl halide and dimethyl sulfide etc. were efficiently generated in situ, resulting in the formation of Me2SCuX. Oxidation of Cu(0) in reacting with both benzyl halide (starting material) and methyl halide (in situ generated product) to Cu(I) followed by complexing with dimethyl sulfide (in situ generated product) could explain the formation of Me2SCuX. In particular we found out that heterogeneous reaction of Me2SCuX and arenediazonium tetrafluoroborate in acetonitrile was so effective to afford corresponding bromoaromatics under mild conditions.

• 대한화학회지
• /
• 제20권4호
• /
• pp.295-298
• /
• 1976

Organothioenamine phosphonate와 styrene oxide 와의 반응에서 얻어진 생성물의 구조를 규명한 결과 그것이 cyclopropane 유도체임을 알았다. 이것은 반응이 styrene oxide에 대한 thioenamine phosphonate의 친핵공격에 의해서 생긴 산소 음이온이 다시 인 원자를 공격함으로서 중간체로 betain이 형성 된다음 이어서 약한 P-C 결합이 끊어지면서 생성물로 이끌어져 감을 가리켜 주고있다. 또한 생성물의 광학활성을 조사한 결과는 우회전성 이어서 이 반응은 중간체에서 생긴 benzyl carbon의 입체적 효과를 받으며 어디까지나 안정한 경로를 거쳐서 이끌어져 감을 알 수 있었다.