• 대한화학회지
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• 제28권6호
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• pp.355-360
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• 1984

Methylene blue(MB$^+$)와 tetraphenylborate(TPB$^-$)이 공존하는 묽은 수용액에서 MB+만의 흡수스펙트럼보다는 장파장 쪽에서 스펙트럼의 변화를 관찰하고, 이를 나타내는 화학종에 관한 연구를 흡수분광법으로 수행하였다. 소수성이 큰 이들 두 이온의 물의 구조를 덜 깨뜨리려는 힘에 의하여 이온쌍으로 되고 더 나아가 전자밀도가 높은 TPB$^-$로 부터 전자가 옮겨진 전하이동 착물이 그것일수도 있다. 그러나 MB$^+$만의 최대 흡수 파수를 기준으로 1,000cm$^{-1}$ 만큼 높고 낮은 두 흡수띠를 보였으므로 중이온쌍, (MB-TPB)$_2$가 새로운 흡수를 보이는 주된 화학종으로 생각되었다.

• Archives of Pharmacal Research
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• 제19권6호
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• pp.435-440
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• 1996

The effect of benzalkonium chloride on skin permeability of partially modified antisense phosphorothioate oligonucleotides (PS-ODN), which are designed as scar formation inhibitor, was investigated using Franz Diffusion Cell. When the concentration ratio of PS-ODN-quarternary ammonium salt complex is more than 1:100, the apparent partition coefficient (APC) of each complex was increased in the following order; tetraphenyl phosphonium chloride (TPP) < cetyltrimethyl ammonium bromide(CTAB) < benzalkonium chloride (BZ). The permeability of PS-ODN through the rat skin increased in the presence of BZ. The fluxs of PS-ODN with BZ were increased by addition of Pluronic F 68 or Triton X-100 to phosphate buffered saline (PBS), respectively. When the mole ratio of PS-ODN to BZ is 1:10, the fluxs penetrated of PS-ODN with BZ was greatest. The increase of the permeability in the presence of BZ might be due to the formation of lipophilic ion-pair complex between PS-ODN and BZ. By regulation of mole ratio of PS-ODN to BZ, the development of topical dosage forms using PS-ODN as scar formation inhibitor will be possible with minimal systemic exposure.

• 대한화학회지
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• 제37권9호
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• pp.793-799
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• 1993

$C_{18}$ 칼럼을 정지상으로 사용한 역상 액체크로마토그래피에서 수소성이 약한 tetramethylammonium bromide(TMAB)를 반대이온으로 사용하여 방향족 술폰산들의 머무름기구를 조사해 본 결과, 이온-쌍 모델이 우세하였다. 분석물질들의 용량인자는 반대이온의 종류와 농도, 메탄올과 co-anion의 농도, 분석물질속에 있는 작용기의 종류와 위치 및 이동상의 pH 등의 영향을 받았다. 최적 조건하에서 분석물질들의 혼합물을 효과적으로 분리할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2722-2726
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• 2011

Plasticized poly(vinyl chloride), PVCs, with different membrane compositions tested for use in the construction of an ion-selective sensor for the determination dibucaine. A prepared membrane with dioctyl phthalate-PVC and ion-pair of N-(1-naphthyl)ethylenediamine dihydrochloride-tetraphenyl borate had a good potential to acts as a potentiometric sensor for the analysis of dibucaine. A linear relationship was obtained between potential and logC varying between $1.0{\times}10^{-6}$ and $1.0{\times}10^{-2}$ M dibucaine with a good repeatability and reproducibility. The sensor was applied for the determination of the drug in pharmaceuticals and biological fluids such as plasma and urine samples with satisfactory results. The drug electrode has also been used to study the interaction of bovine serum albumin (BSA) with dibucaine. The saturated quantities of dibucaine binding were 13.04, 5.30 and 9.70 mol/mol in 0.01, 0.02 and 0.1% of protein, respectively.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2571-2574
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• 2010

We investigate the mechanism of $S_NAr$ fluorination reactions under the influence of protic solvents and ions. We find that counterion or protic solvent alone retards the $S_NAr$ reactions, but together they may promote the reaction. In this mechanism, the protic solvent acts on the counterion as a Lewis base, and the nucleophile reacts as an ion pair. We also show that an anion (mesylate) may exhibit catalytic effects, suggesting the role of ionic liquids for accelerating the $S_NAr$ reactions.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.313.2-313.2
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• 2002

Environmentally benign protein staining method in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) using both an acidic dye, zincon (ZC) and a basic dye. ethyl violet (EV) is described. It is based on a counter ion-dye staining technique that employs oppositely charged two dyes to form an ion-pair complex. The selective binding of the free dye molecules to proteins in an acidic solution produces bluish violet colored bands. It is a rapid procedure, involving only fixin and staining steps that are completed in 45 min. (omitted)

• E2M - 전기 전자와 첨단 소재
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• 제7권2호
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• pp.100-106
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• 1994

A bilayer film consisting of a layer of a-Se$_{75}$ Ge$_{25}$ with a surface layer of silver -100[.angs.] thick and a monolayer film of a-Se$_{75}$ Ge$_{25}$ are irradiated with 9[keV] Ga$^{+}$ ion beam. The Ga$^{+}$ ion (10$^{16}$ [ions/cm$^{2}$] exposed a-Se$_{75}$ Ge$_{25}$ and Ag/a-Se$_{75}$ Ge$_{25}$ thin films show an increase in optical absorption, and the absorption edge on irradiation with shifts toward longer wavelength. The shift toward longer wavelength called a "darkening effect" is observed also in film exposure to optical radiation(4.5*10$^{20}$ [photons/cm$^{2}$]). The 0.3[eV] edge shift for ion irradiation films is about twice to that obtained on irradiation with photons. These large changes are primarily due to structural changes, which lead to high etch selectivity and high sensitivity.

• 분석과학
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• 제10권4호
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• pp.231-239
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• 1997

역상 이온쌍 고성능 액체크로마토그래피에 의해 3차 아민들과 4차 암모늄염들을 분리하고 정량하였다. 시료들은 간접분광광도법에 의해 검출하였다. 검출 시약과 이온쌍 시약으로는 염화벤질 트리메틸암모늄(BTMACl)과 도데실황산나트륨(DDSANa)을 사용하였다. 전해커패시터의 전해액 중에 포함되어 있는 이들 아민과 암모늄염의 분리 및 정량은 메탄올-물(40:60) 용액에 DDSANa를 0.010M, BTMACl을 0.004M 되게 용해시키고 염화암모늄-암모니아 완충용액(0.05M)으로 pH를 8.5되게 만든 용리액으로 Supelco LC-18이나 ${\mu}$-Bondapak phenyl 컬럼을 통하여 용리시킴으로써 가능하였다. 전해 커패시터들의 전해액을 분석하여 얻은 분석 값의 4차 암모늄염을 첨가하여 만든 커패시터는 임피던스 0.08~0.13의 성능이 우수한 커패시터가 됨도 발견함으로써 분석이 잘 이루어 졌음을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2483-2487
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• 2010

Pseudo-first-order rate constants ($k_{obsd}$) were measured spectrophotometrically for nucleophilic substitution reactions of 4-nitrophenyl picolinate (6) with alkali metal ethoxides (EtOM, $M^+\;=\;K^+$, $Na^+$ and $Li^+$) in anhydrous ethanol at $25.0{\pm}0.1^{\circ}C$. The plot of $k_{obsd}$ vs. [EtOM] exhibits upward curvature regardless of the nature of $M^+$ ions. However, the plot for the reaction of 6 with EtOK is linear with significantly decreased $k_{obsd}$ values when 18-crown-6-ether (18C6, a complexing agent for $K^+$ ion) is added in the reaction medium. Dissection of $k_{obsd}$ into $k_{EtO^-}$ and $k_{EtOM}$ (i.e., the second-order rate constant for the reaction with dissociated $EtO^-$ and ion-paired EtOM, respectively) has revealed that ion-paired EtOM is 3~17 times more reactive than dissociated $EtO^-$. The reaction has been proposed to proceed through a 5-membered cyclic transition state, in which $M^+$ ion increases the electrophilicity of the reaction site. Interestingly, $Na^+$ ion exhibits the largest catalytic effect. The presence of a nitrogen atom in the pyridine moiety of 6 has been suggested to be responsible for the high $Na^+$ ion selectivity.

• Bulletin of the Korean Chemical Society
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• 제22권7호
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• pp.669-672
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• 2001

Pseudo-first-order rate constants have been measured spectrophotometrically for the title reactions. The plot of kobs vs the concentration of alkali metal ethoxides is linear for the reactions performed in the presence of complexing age nt, 18-crown-6 ether, but curved upwardly for the corresponding reactions performed in the absence of the complexing agent, indicating that the alkali metal ions studied in this study behave as a catalyst. The catalytic effect was found to increase in the order Li+ << K+ ${\leq}$ Na+. Second-order rate constants were determined for the reactions with dissociated free ethoxide (kEtO-) and with ion paired alkali metal ethoxides (kEtO-M+ ) from ion pairing treatments. The magnitude of catalytic effect (kEtO-M+/kEtO-) was found to be 2.3, 9.5 and 8.7 for the reaction of 8-(5-nitroquinolyl) 2-furoate, while 1.4, 3.6 and 4.2 for that of 4-nitrophenyl 2-furoate, indicating that the catalytic effect is larger in the reaction of the former substrate than in that of the latter one. The larger catalytic effect was attributed to two possible complexing sites with alkali metal ions in the former substrate.