• 한국연초학회지
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• 제6권1호
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• pp.25-31
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• 1984

The volatile aroma components were isolated from Korean flue-cured tobacco (N.C. 2326) by using a vacuum steam distillation method. Individual aroma components were identified by GCIMS and comparison of gas chromatowaphic retention time with those of the authentic samples. Sensory analysis showed that a vacuum steam-distilled product of Flue-cured tobacco had a typical haylike, floral and fruity aroma. Among 62 compounds identified, major compounds included neophytadiene, benzyl alcohol, ethyl acetate, phenyl ethyl alcohol, ethyl alcohol, ethyl formate, acetic acid, solanone, 2-acetyl pyrrole, $\beta$-ionone epoxide, 2, 4-heptadienal (2 isomers), megastigmatrienone (4 isomers), furfural and total amounts of 13 compounds were about 80%.

• 한국염색가공학회지
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• 제2권1호
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• pp.31-36
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• 1990

산화제를 함유한 셀룰로우스 아세테이트 필름을 피롤 증기 속에 노출시킴으로써 전도성 셀룰로우스/폴리피롤 복합체 필름을 합성하고 폴리피롤의 형성을 IR 및 전자현미경을 사용하여 확인했다. 복합체 내에 존재하는 폴리피롤의 형태는 사용한 산화제의 종류에 따라 다르게 나타났다. 산화제로 사용한 몇 가지 금속염화물 중에서 염화제 2철이 높은 전도도를 가지는 복합체를 합성하는데 가장 효과적이며 50중량 퍼센트의 염화제 2철을 첨가해서 제조한 복합체 필름의 전기전도도는 $10^{-2}S/cm$에 달한다.

• Bulletin of the Korean Chemical Society
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• 제20권9호
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• pp.1056-1060
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• 1999

New water soluble and highly electron deficient cobalt(II) tetrakis-(1,2,5,6-tertrafluoro-4-NN'N"-trimethyla-nilinium)-β-octabromoporphyrin [Co II (Br8TTFP)(Y)2] was synthesized and used for the electrocatalytic reduction of dioxygen. The first reduction of synthesized [Co II (Br8TTFP)(Y)2] involves one electron process to give metal centered [Co I (Br8TTFP)(Y)2]. The reduction of potential [E1/2 = -0.32 V] of [Co II (Br8TTFP)(Y)2] shifts positively 370 mV compared with that of [Co II (TTFP)(Y)2] due to the substituted bromide to β-pyrrole positions. The electrochemically reduced [Co I (Br8TTFP)(Y)2] binds dioxygen and catalytically reduces it to HOOH by 2e - transfer. Cyclic and hydrodynamic voltammetry at a glassy carbon electrode in dioxygen-saturated aqueous solutions are used to study the electrocatalytic pathway.

• Bulletin of the Korean Chemical Society
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• 제12권5호
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• pp.537-540
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• 1991

Electrophilic methylation reactions of five-membered heteroaromatic compounds, furan, pyrrole and thiophene, with the dimethylfluoronium ion, ${CH_3}{FCH_3}(+), have been investigated theoretically by the MNDO method. The site selectivity of ${\alpha}, {\beta}$ and heteroatom (X) is related to charge density of the site, indicating that the site selectivity is dictated by electrosatic interaction between two reaction centers. The reactivity order between the three heteroaromatics can not be determined decisively since the order differs depending on which site is compared, with relatively low activation enthalpies, ${\Delta}{H^\neq}$= 20-30 kcal/mol, in all cases. These site and substrate selectivity behaviors are consistent with the gas-phase experimental results.

• Bulletin of the Korean Chemical Society
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• 제19권2호
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• pp.183-188
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• 1998

Incorporation of metalloporphyrins into polypyrrole (PPy) film was achieved either by electropolymerization of pyrrole in the presence of metal-tetra(sulfonatophenyl)porphyrin anion (MTSPP, M=Co, Fe) or by metalizing hydrogenated tetra(4-sulfonatophenyl)porphyrin anion (H2TSPP) doped into PPy through ion-exchange. Electrochemical reduction of oxygen on the PPy doped with metallo porphyrin (PPy-MTSPP) was studied in acidic and basic solutions. Oxygen reduction on PPy-MTSPP electrodes appeared to proceed through a 4-electron pathway as well as a 2-electron path. In acidic solutions, the overpotential for O2 reduction on PPy-CoTSPP electrode was smaller than that on gold by about 0.2 V. In basic solutions the overpotential of the PPy-CoTSPP electrode in the activation range was close to those of Au and Pt. The limiting current was close to that of Au. However, polypyrrole doped with cobalt-tetra(sulfonatophenyl)porphyrin anion (PPy-CoTSPP) or with iron-tetra(sulfonatophenyl)porphyrin anion (PPy-FeTSPP) was found to have limited potential windows at high temperatures (above 50 ℃), and hence the electrode could not be held at the oxygen reduction potentials in basic solutions (pH 13) without degradation of the polymer.

• Bulletin of the Korean Chemical Society
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• 제20권3호
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• pp.276-280
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• 1999

The different core-modified porphyrins 21-thia-23-carba-12-aza-5,10-dimesityl-15,20-diphenylporphyrin (6), and their N(12)-methyl derivatives (8) were synthesized by acid-catalyzed [3+1] condensation of the corresponding 16-thia-5,10-dimesityltripyrromethanes and 2,4-bis[(α-hydroxy-α-phenyl)methyl]pyrrole. Spectroscopic evidence indicates the existence of two different tautomeric forms at room temperature in porphyrin (6). A third form of tautomer was observed when the temperature was lowered to 223 K. The most stable tautomer is one in which the nitrogenic proton resides outside the core of the macrocycle. The ratio of the three different tautomers (outer N-H/ two inner N-H, i.e. 6/12/13) was 1/l/0.5 in the case of (6) while the ratio of 1/l/0.3 was observed in the case of (10). In the case of 21-oxa-23-carba-12-aza-5,10,15,20-tetraphenylporphyrin (7), the only stable tautomeric form observed by 1H NMR was the one that nitrogenic proton resides inside the core on

• Bulletin of the Korean Chemical Society
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• 제19권3호
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• pp.314-319
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• 1998

One flask synthesis of dithienylmethane and difurylmethane is reported. The reaction of aldehydes with excess furan or thiophene affords the meso-phenyldithienylmethane (DTM) and meso-phenyldifurylmethane (DFM), respectively. The reaction is catalyzed with trifluoroacetic acid or with BF3·O(Et)2. An acyl group is selectively introduced in 1 and 9 position of difurylmethane and dithienylmethane by use of an acid chloride and tin (IV) chloride. The reduction of resulting 1,9-bisacyldifurylmethane or 1,9-bisacyldithienylmethane affords the corresponding 1,9-bis-diol. An acid catalyzed condensation of diol with meso-phenyldipyrromethane followed by oxidation with DDQ gives the porphyrins. The reaction resulted meso-5,10,15,20-tetraphenyl-21,22-dithiaporphyrin (SSNN) or 15-mesityl-5,10,20-triphenyl-21,22-dioxaporphyrin (OONN), respectively. The formation of small amount of meso-tetraphenylporphyrin (TPPH2) is also observed. The formation of TPP indicates that meso-phenyldipyrromethane is reversibly cleaved and form pyrrole and pyrrylbenzylcarbocation during the condensation. The proton nmr and electronic spectrum of the SSNN and OONN porphyrins are somewhat different from the previously synthesized meso-5,10,15,20-tetraphenyl-21,23-dithiaporphyrin (SNSN) or meso-5,10,15,20-tetraphenyl-21,23-dioxaporphyrin (ONON).

• 대한방사성의약품학회지
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• 제7권2호
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• pp.141-146
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• 2021

With increasing interest in fluorinated compounds, nucleophilic fluorination reaction has been generally used for synthesizing fluorine-containing chemicals. However, alkali metal fluorides (MFs) generally have low solubility and reactivity in organic solvent. To overcome these problems, various phase transfer catalysts (PTCs) have been investigated. Calix-arene is known as to capture the metal cation(M⁺), and therefore in this review, we would like to introduce several kinds of calix-arene based PTCs, such as bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA), oligo-ethylene glycol linked bis-triethyleneglycol crown-5-calix[4]arene (BTC5A), and ionic liquid functionalized calix-arene based catalyst, as well as ion-pair receptor crown-6-calix[4]arene-capped calix[4]pyrrole.

• 생명과학회지
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• 제16권2호
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• pp.206-212
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• 2006

본 연구를 통해 항 경련 활성을 보이는 8-aza-bicyclo[3,2,1]octan-3-one 구조를 모체로 하여 생리활성 및 구조적 특이성을 가진 8-aza-bicyclo[3,2,1]octan-3-one 화합물을 합성하고자 하였다. 본 논문에서는 ethylenediamine 1을 2,5-dimethoxyte-trahydrofuran과 1,3-acetonedicarboxylic acid을 반응시켜 8-(2-pyrrol-1-yl-ethyl)-8-aza-bicyclo[3,2,1]octan-3-one 2(yield ; 5.0%)와 1,2-di-8-aza-bicyclo[3,2,1]octan-3-onyl)ethane 3(yield ; 17.0%)을 합성하였다. 1,3diaminopropane 4의 경우에는, 8-(3-pyrrol-1-yl-propyl)-8-aza-bicyclo[3,2,1]octan-3-one 5(yield ; 6.0%)와 1,3-di-8-aza-bicyclo[3,2,1]octan-3-onyl)propane 6 (yield; 21.0%)을, 그리고 1,8-diaminooctane 7의 경우에는 8-(-8-pyrrol-1-yl-octyl)-8-aza-bicyclo[3,2,1]octan-3-one 8(yield; 2.6%)과 1,8-di-8-aza-bicyclo[3,2,1]octan-3-onyl)octane 9(yield; 24.9%)를 합성할 수 있었다. Diaminoalkanes(1,.4, 7)의 반응에서 보면 실온에서 반응을 진행시켰기에 pyrrole 유도체보다는 8-aza-bicyclo[3,2,1]octan-3-one 유도체의 합성이 보다 유리한 결과를 나타냈다. 그리고 탄소 chain이 길수록 N 원자에 전자를 잘 밀어주어 활성이 더 좋았으며 탄소 steric effect도 작기 때문에 생성물의 yield가 더 높았다. Diaminobenzene(10, 14) 역시 diaminoalkane의 반응과 같이 p-phenylenediamine 10을 2,5-dimethoxytetrahydrofuran, 그리고 1,3-acetonedicarboxylic acid과 반응시켜 p-dipyrrolylbenzene 11(yield; 4.0%), 8-(4-pyrrol-1-yl-phenyl)-8-aza-bicyclo[3,2,1]octan-3-one 12(yield; 12.0%), 1,4-di-(8-aza-bicyclo[3,2,1]octan-3-onyl)-benzene 13(yield; 59.0%)을 합성하였고, m-phynylenediamine 14의 경우에도 8-(3-pyrrol-l-yl-phenyl)-8-aza-bicyclo[3,2,1]octan-3-one 15(yield; 2.0%)와 1,3-di-(8-aza-bicyclo[3,2,1]octan-3-onyl)-benzene 16(yield; 28.0%)을 합성할 수 있었다. 그러나 o-phynylenediamine 17의 경우에는 8-aza-bicyclo[3,2,1]octan-3-one ring들의 steric hindrance의 영향에 의해 1,3-di-8-aza-bicyclo[3,2,1]octan-3-onyl)benzene은 합성되지 않았다.

• 공업화학
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• 제5권5호
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• pp.764-771
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• 1994

친핵성용매하에서 p-toluenesulfonic acid나 bezensulfonic acid와 같은 유기산을 지지전해질 겸 dopant로 사용하여 전도성 Polypyrrole필름을 전해중합하였고 분해 특성과 기계적 물성증가에 대하여 고찰하였다. Dimethyformamide/p-toluenesulfonic acid에서 합성한 polypyrrole 필름이 전도도 10-40S/cm, 인장강도 $25N/mm^2$. 연신율은 10%로 가장 좋은 특성을 나타내었다. 또한 전해중합시 최적 조건은 0.5M의 pyrrole과 0.5M의 p-toluenesulfonic acid를 첨가하여 정전류법에서는 $2mA/cm^2$의 전류밀도가, 정전위법으로는 0.9V vs. $Ag/Ag^+$에서 중합할 때였으며 생성된 필름은 공기중에서 안정하였고 도핑, 탈-도핑이 가역적이어서 2차 전지로서의 특성을 갖고 있었다. 온도에 따른 분해과정이 1차 반응으로 dopant 음이온이 분해반응에 관여하지 않아 산화안정성이 좋았으며 분해활성화 에너지는 $1.01JK^{-1}mol^{-1}$, $25^{\circ}C$에서의 분해속도상수는 $3.1{\times}10-7min^{-1}$였다. 여러 가지 host polymer와의 composite를 검토한 결과 인장강도는 50%, 연신율은 100% 정도로 기계적 물성을 증가시킬 수 있었다.