• Journal of Plant Biology
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• 제19권4호
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• pp.95-99
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• 1976

This work deals with different extraction media and reaction mixtures on photosystem II activity of Spinach chloroplasts. The photoreduction rate of ferricyanide and DPIP by intact chloroplasts which extracted with four kinds of extraction media; S-Tris-N pH 7.2, 8.0, S-Tricine-N pH 7.2, 8.0, was measured in five kinds of reaction mixtures; S-Tris-N pH 7.2, 8.0, S-Tricine-N pH 7.2, 8.0, 0.05 M-Tris pH 7.2. The extraction medium which shows the highest photoreduction rate was S-Tris-N at pH 7.2 and S-Tricine-N at pH 8.0. As to the reaciton mixture, S-Tricine-N pH 8.0 showed the highest rate. On the complex effects of extraction media and reaction mixtures, the highest photordeuction rate of Hill oxidant by intact chloroplasts was obtained by S-Tris-N pH 7.2 extraction medium and S-Tricine-N pH 8.0 reaction mixture. The second highest activity was obtained by S-Tricine-N pH 8.0 extraction medium and reaction mixture.

• 대한화학회지
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• 제36권1호
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• pp.81-86
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• 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.

• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.851-856
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• 2002

The Reaction of S-methyl-S-cysteine(L-Smc) with racemic $s-cis-[Co(demba)Cl_2]-1$ (Hydmedba = $NN'-dimethylethylenediamine-NN'-di-\alpha-butyric$, acid) yields ${\Delta}$-s-cis-[Co(dmedba)(L-Smc)] 2 with N, O-chelation. Oxidation of sulfur of 2 with $H_2O_2$ in a 1 : 1 mole ratio gives ${\Delta}$-s-cis[Co(dmedba)(L-S(O)mc)] 3 having an uncoordinated sulfenate group. Oxidation of sulfur of L-Sm with $H_2O_2in$ a 1: 1 mole ratio produces S-methyl-L-cysteinesulfenate (L-S(O)me) 5. Direct reaction of 1 with 5 in basic medium gives an N.O-chelated ${\Delta}$s-cis[Co(dmedba)(L-S(O)mc)-N.O], which turmed out be same as obtained by oxidation of 2, while an N, S-chelated ${\Delta}$-s-cis-[Co(dmedba)(S-S(O)mc)-N,O] complex 4 is obtained in acidic medium from the reaction of 1 with 5. This is one of the rare $[$Co^{III}$(N_2O_2-type$ ligand)(amino acid)] type complex preparations, where the reaction conditions determine which mode of N, O and N, S caelation modes is favored.

• 대한화학회지
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• 제30권4호
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• pp.383-388
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• 1986

2-phenylethylarenesulfonates와 피리딘과의 아세토니트릴 용매중에서의 반응속도를 40∼60${\circ}C$, 1 ~ 2,000 bar에서 전기 전도도법으로 측정하였다. 반응속도는 온도가 높아지고 압력이 커짐에 따라 증가하였으며 아세톤 용매내에서 benzyl benzenesulfonate와 파라딘과의 반응속도보다 느렸다. 2-phenylethyl m-nosylate의 활성화 부피${\Delta}V^{\neq}$와 활성화 엔트로피 TEX>${\Delta}S^{\neq}$는 benzenesuflonate보다 음의 값으로 컸다. 따라서 본 반응의 2-phenylethyl계가 전이 상태에서 벤질계보다 $S_N2$성이 크다고 추정된다. Hammett도시한 결과는 압력의 증가에 따라 값이 감소하여 $S_N2$성이 증가하였다. 이들의 모든 결과로 부터 고압하에서의 본 반응은 $S_N2$메카니즘으로 진행되며 압력의 증가는 $S_N2$반응성을 더욱 조장하였다.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1535-1538
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• 2009

We present calculations for $S_N$2/E2 reactions in protic solvents (t-butyl alcohol, ethylene glycol). We focus on the role of the hydroxyl (-OH) groups in determining the $S_N$2/E2 rate constants. We predict that the ion pair E2 mechanism is more favorable than the naked ion E2 reaction in ethylene glycol. E2 barriers are calculated to be much larger (~ 9 kcal/mol) than $S_N$2 reaction barriers in protic solvents, in agreement with the experimental observation [Kim, D. W. et al. J. Am. Chem. Soc. 2006, 128, 16394] of no E2 products in the reaction of CsF in t-butyl alcohol.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.583-592
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• 2003

The gas phase identity nucleophilic substitution reactions of halide anions (X = F, Cl, Br) with cyclopentadienyl halides (1) are investigated at the B3LYP/6-311+G**, MP2/6-311+G** and G2(+)MP2 levels involving five reaction pathways: σ-attack $S_N2$, β-$S_N$2'-syn, β-$S_N$2'-anti, γ-$S_N$2'-syn and γ-$S_N$2'-anti paths. In addition, the halide exchange reactions at the saturated analogue, cyclopentyl halides (2), and the monohapto circumambulatory halide rearrangements in 1 are also studied at the same three levels of theory. In the σ-attack $S_N2$ transition state for 1 weak positive charge develops in the ring with X = F while negative charge develops with X = Cl and Br leading to a higher energy barrier with X = F but to lower energy barriers with X = Cl and Br than for the corresponding reactions of 2. The π-attack β-$S_N$2' transition states are stabilized by the strong $n_C-{\pi}^{*}_{C=C}$ charge transfer interactions, whereas the π-attack γ-$S_N$2' transition states are stabilized by the strong $n_C-{\sigma}^{*}_{C-X}$ interactions. For all types of reaction paths, the energy barriers are lower with X = F than Cl and Br due to the greater bond energy gain in the partial C-X bond formation with X = F. The β-$S_N$2' paths are favored over the γ-$S_N$2' paths only with X = F and the reverse holds with X = Cl and Br. The σ-attack $S_N2$ reaction provides the lowest energy barrier with X = Cl and Br, but that with X = F is the highest energy barrier path. Activation energies for the circumambulatory rearrangement processes are much higher (by more than 18 kcal $mol^{-1}$) than those for the corresponding $S_N2$ reaction path. Overall the gas-phase halide exchanges are predicted to proceed by the σ-attack $S_N2$ path with X = Cl and Br but by the β-$S_N$2'-anti path with X = F. The barriers to the gas-phase halide exchanges increase in the order X = F < Br < Cl, which is the same as that found for the gas-phase identity methyl transfer reactions.

• 대한전기학회논문지
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• 제45권2호
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• pp.242-248
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• 1996

The properties of TiN/TiSi$_{2}$ bilayer formed by a rapid thermal annealing is investigated when thin SiO$_{2}$ film exists at the Ti-Si interface. The competitive reaction for the TiN/TiSi_2 bilayer occurs above 600 .deg. C. The thickness of the TiSi$_{2}$ layer decreases with increasing SiO$_{2}$ film thickness and also decreases with increasing anneal temperture When the competitive reaction for the TiN/TiSi$_{2}$ bilayer is occured by rapid thermal annealing, the composition of TiN layer represents TiN$_{x}$O$_{y}$ due to the SiO$_{2}$ layer at the Ti-Si interface but the structures of the TiN and TiSi$_{2}$ layers were not changed.d.d.

• 대한화학회지
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• 제23권1호
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• pp.37-41
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• 1979

Benzyl m-nitrobenzenesulfonate와 N,N-dimethylaniline類와의 反應速度를 아세톤 溶媒에서 電氣傳導度法으로 測定하였다. N,N-디메틸아닐린의 反應性에 關한 置換基效果와 直線 自由에너지 關係를 考察하였다. 反應速度常數 k는 2.55∼487 $10^{-4}l{\cdot}mol^{-l}{\cdot}sec^{-1} (35^{\circ}C)$였으며 置換基가 電子를 주는 能力이 클수록 反應은 빨랐다. Hammett 도시에서 置換基常數 ${\sigma}$와 ${\sigma}p$-MeO = -0.35의 새로운 값을 使用했을때 ${\rho}$ = -1.37의 좋은 直線이 얻어졌다. 本反應의 경우 r값은 브롬화벤질에 比해 큰 값을 가졌다. Bronsted 圖示에서 溶媒效果에 基因된 p-MeO基를 除外하고는 좋은 直線이 얻어졌으며 C${\cdot}{\cdot}{\cdot}$O 結合의 쪼개짐이 結合 形成보다 優先的인 $S_N2$ 轉移狀態를 갖는다고 推定된다.

• Bulletin of the Korean Chemical Society
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• 제21권9호
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• pp.919-922
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• 2000

The cyclization reaction of N-(2-hydroxyethyl)-N'-phenylthioureas 2 containingambident nucleophile was ex-amined in the combination of a variety ofbases and p-toluenesulfonyl chloride (TsCl).N-(2-Hydroxyeth-yl) thioureas 2 were readily obtained in high yields from the reaction of the corresponding 1,2-aminoalcohols with phenyl isothiocyanate, avoiding the need for O-protection.The use of a one-pot reaction (NaOH/TsCl) was found to be most effective in producing the requisite 2-phenylaminothiazolines (S-cyclization) 3 in the case ofthioureas 2a-2e derived from N-unsubstituted aminoalcohols,while in the thioureas 2f and 2g prepared from N-substituted aminoalcohols the combination of Et3N and TsCl led to the S-cyclization products.

• 한국운동역학회지
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• 제17권2호
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• pp.207-216
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• 2007

The purpose of this study was to biomechanical analysis Judo's Kuzushi throwing motion in order to increase the effectiveness of Nage-waja(throwing technique). The Tori was a Judo player with 18 years experience(4th degree) while the Uke was a player with 2 years experience(1st degree). The kinematic data was captured using the Vicon motion system (7 cameras) and the kinetics were recorded by force plates(2 AMTI). The following were the results; While leaning to the front the subject's trunk's angle was $14.5^{\circ}$, the lower limbs angle was $23.8^{\circ}$, knee angle was $179.6^{\circ}$ and the vertical reaction of the left leg was 325.42N(BW 0.34) and the right leg was 233.7N(BW 0.47). While leaning back the subject's trunk's angle was $11.3^{\circ}$, the lower limbs angle was $4.1^{\circ}$, knee angle was $1761^{\circ}$ and the vertical reaction of the left leg was 299.53N(BW 0.43) and the right leg was 441.7N(BW 0.64). While leaning to the left the subject's trunk's angle was $30.8^{\circ}$, the lower limbs angle was $2.7^{\circ}$, knee angle was $175.2^{\circ}$ and the vertical reaction of the left leg was 711N(BW 1.03) and the right leg was 9.2N(BW 0.01). While leaning to the right the subject's trunk's angle was $36.5^{\circ}$, the lower limbs angle was $10.4^{\circ}$, knee angle was $175.2^{\circ}$ and the vertical reaction of the left leg was 13.2N(BW 0.02) and the right leg was 694.7N(BW 1.01). While leaning to the left front corner the subject's trunk's angle was $19.8^{\circ}$ (front) and $15.1^{\circ}$ (left), the lower limbs angle was $17.8^{\circ}$ (front) and $2.4^{\circ}$ (left), knee angle was $177.8^{\circ}$ (front) and $173.9^{\circ}$(left), and the vertical reaction of the left leg was 547.4N(BW 0.8) and the right leg was 117.8N(BW 0.17). While leaning to the right front corner the subject's trunk's angle was $15.4^{\circ}$ (front) and $17.7^{\circ}$ (right), the lower limbs angle was $21.1^{\circ}$, (front) and $5.7^{\circ}$ (right), knee angle was $175.5^{\circ}$ (front) and $178.9^{\circ}$(right), and the vertical reaction of the left leg was 53N(BW 0.08) and the right leg was 622.4N(BW 09). While leaning to the left rear corner the subject's trunk's angle was $9.2^{\circ}$ (back) and $13.8^{\circ}$ (left), the lower limbs angle was $2^{\circ}$, (back) and $5.7^{\circ}$ (left), knee angle was $175.5^{\circ}$ (back) and $172.8^{\circ}$(left), and the vertical reaction of the left leg was 698.2N(BW 1.02) and the right leg was 49.6N(BW 0.07). While leaning to the right rear corner the subject's trunk's angle was $8.9^{\circ}$ (back) and $19.6^{\circ}$ (right), the lower limbs angle was ${0.6^{\circ}}_"$ (back) and $3.1^{\circ}$ (right), knee angle was $174.6^{\circ}$ (back) and $175.6^{\circ}$(right), and the vertical reaction of the left leg was 7.2N(BW 0.01) and the right leg was 749.4N(BW 1.09). It was observed that during the Judo motion Kuzushii the range of the COM varied from $26.5{\sim}39.9cm$. It was concluded that the upper body leaned further than the lower body as there was knee extension. There was high left leg reaction forces while leaning to the left and likewise for the right side. It was therefore deduced that the Kuzushi was a more effective throwing technique for the left side.