• Journal of the Korean Graphic Arts Communication Society
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• v.19 no.1
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• pp.17-27
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• 2001

플라티늄포르피린 핵과 주위에 8, 16, 32 그리고 64 개의 벤질 단위를 갖는 새로운 덴드리머를 압력 감지형 페인트에 사용할 발광체로 합성하였다. 플라티늄포르피린 핵을 갖는 제 1 세대의 덴드리머는 Lindsey형 합성법을 이용하여 제조하였으며, 제 2 세대에서 제 4 세대까지의 플라티늄포르피린 핵을 갖는 덴드리머는 플라티늄 테트라키스(3,5-디히드록시페닐)포르피린을 적합한 덴드론 브로마이드와 Williamson 에테르 합성법에 따라 알킬화반응시켜 제조하였다. 이러한 에테르 연결의 생성 반응들은 $K_2$CO$_3$와 18-크라운-6를 사용하여 아세톤 용매에서 질소 기류 하에서 6$0^{\circ}C$에서 수행하였을 때 가장 좋은 결과를 주었다. 그리고 이렇게 합성한 덴드리머들을 $^1$H-NMR, $^{13}$C-NMR, Mass spectrum 이용하여 구조를 확인하고, 그리고 UV-VIS spectroscopy를 이용하여 분광학적인 특성을 조사하였다.

• Journal of the Korean Chemical Society
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• v.39 no.9
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• pp.698-704
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• 1995

The ion-selective membrane fabricated with 33 wt% PVC, 66 wt% o-NPOE and 1 wt% 4'-benzothiazolylbenzo-15-crown-5 (TB15C5) as a neutral carrier exhibited an enhanced selectivity to potassium ion over sodium ion compared to those prepared with other 15-crown-5 or 18-crown-6 derivatives. The potentiometric properties (response slope, selectivity, detection limits and lifetime) of TB15C5-based ISE membranes along with those based on valinomycin, benzo-15-crown-5 (B15C5), 4'-aminobenzo-15-crouwn-5 (AB15C5), benzo-18-crown-6 (B18C6), dibenzo-18-crown-6 (DB18C6) and bis[(benzo-15-crown-5)-4'-ylmethyl]pimelate (PI-Ⅱ) ionophores were carefully examined under the same experimental conditions. The enhanced selectivity of TB15C5-based membrane to potassium is explained in terms of the effect of the benzothiazol functional group and the distribution coefficients of metal ions.

• Journal of the Korean Applied Science and Technology
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• v.22 no.3
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• pp.219-227
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• 2005

Competitive solvent extraction of the mixure of alkali metal and alkaline earth cation from water into organic solvent containing the crown ether carboxylic acid and anlogous crown ether phosphonic acid was investigated as follows. The lipophilic group is found to strongly influence to the selective extraction in the mixed systems from only alkali metal cation for sym-(n-decyldibenzo)-16-crown-5-oxyacetic acid $\underline{1}$ to mostly alkaline earth metal cation for sym-bis[4(5)-tert-butylbenzo]-16-crown-5-oxyacetic acid $\underline{3}$. Monoethyl sym-(n-decyldibenzo)-16-crown-5-oxymethylphosphonic acid $\underline{2}$. and monoethyl-sym- bis]4(5)-tert-butylbenzo]-16-crown-5-oxymethylphosphonic acid $\underline{4}$ showed good selectivity for $Na^+$ over $Mg^{2+}$, the second extracted ion. Structural variation in the crown ether phosphonic acid somewhat was influenced to the extraction selectivity in the mixed systems. when variation of the ionized group is influenced in the mixed systems, the selectivity of $Na^+$ as the second extracted ion was much better crown ether carboxylic acid $\underline{1}$ than crown ether phosphonic acid $\underline{2}$, while the efficiency of $Na^+$ extraction was better $\underline{2}$ (83% total loading) than $\underline{1}$ (32%).

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.273-277
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• 1998

The synthesis of hydroxy-terminated poly(propylene carbonate)(HTPPC) was performed by the reaction of propylene carbonate(PC) with alcohol initiator using metal alkoxides, crown ethers and quaternary onium salts as catalysts. The effects of catalyst structure, types and concentration of alcohol, and solvent were investigated. Among the alkoxide catalysts tested, the ones with higher Lewis acidity and with more nucleophilic alkoxide anion showed higher catalytic activity. Mixed catalysts of metal alkoxied and crown ether showed higher conversion of PC than metal alkoxide alone. Quaternary onium salts of bulky cation exhibited higher catalytic activity. High polar solvent showed higher yield of HTPPC and the yield increased with the decrease of [PC]/[Initiator] ratio.

• KSBB Journal
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• v.25 no.5
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• pp.449-452
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• 2010

L-Thyroxine possessing a chiral center, the naturally occurring thyroid hormone has been used for the treatment of thyroid dysfunctions and marketed as levothyroxine (L-thyroxine) sodium salt. In this study, after extraction of levothyroxine tablet as a pre-treatment process, direct enantiomer separation of thyroxine on crown ether derived chiral columns for determination of optical purity was performed using reversed mobile phase with acid additive. The chromatographic method developed in this study was applied in the determination of optical purity of several current domestic and foreign commercialized levothyroxine tablets. Optical purity values of these commercialized L-thyroxine sodium tablets except one were higher than 99 percents.

• Journal of the Korean Chemical Society
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• v.38 no.7
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• pp.509-515
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• 1994

The interactions of 11 kinds of primary and secondary alkylammonium ions with cyclic (12C4, 15C5, 18C6, DT18C6 and DA18C6) and acyclic$(Q_2O_5)$ polyethers were investigated by NMR titration and conductometry. All of the alkylammonium ions under investigation form the relatively stable 1 : 1 complexes with crown ethers and acyclic polyether by H-bond. The interactions of alkylammonium ions with analogeous hosts having different size were in the order of 18C6 > 15C5 > 12C4, and the strengthes of donor atoms toward the alkylammonium ions were in the order of N > O > S. 18C6 forms more favorable interactions with primary alkylammonium ions than secondary alkylammonium ions, otherwise DA18C6 shows the opposite behaviors. The stability constants for complexations of 18C6 with the alkylammonium ions were determined conductometrically in methanol at 25$^{\circ}C$. The major factors affecting the stability of complexes were the type of alkylammonium ions, the length of alkyl-chain and the steric hindrance due to the structure of alkyl groups on complexation.

• Journal of the Korean Chemical Society
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• v.24 no.1
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• pp.34-43
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• 1980

The reaction of thianthrene cation radical perchlorate with thioxanthene in acetonitrile gave thianthrene and dark reddish thioxanthylium ion instead of thioxanthene cation radical. Addition of aromatic nucleophiles such as anisole, aniline, N,N-diethylaniline, catechol, ethylbenzene, to the above mixture yielded the corresponding thioxanthenes with substituent at 9 position. Reactions with dibenzo-18-crown-6-ether, diphenylmercury, and triphenylphosphine gave similar products. However, reactions with aromatics with electron-withdrawing group were either too slow or inert to such a reaction.

• Journal of the Korean Applied Science and Technology
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• v.22 no.1
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• pp.9-14
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• 2005

Competitive solvent extraction of alkaline earth metal cations from water into organic solvent containing the carboxylic acid crown ether and analogous crown ether phosphonic acid monoethyl esters were investigated. sym-(n-Decyldibenzo)-16-crown-5xyacetic acid $\underline{1}$ and monoethyl sym-(n-decyldibenzo)-16-crown-5-oxymethylphosphonic acid $\underline{3}$ are structurally identical except for the ionizable groups. Both of them provide similar extraction behavior in terms of efficiency and selectivity, but monoethyl sym-(n-decyldibenzo)-16-crown-5-oxymethylphosphonic acid $\underline{3}$ showed higher alkaline earth metals loadings at acidic or neutral media. Monoethylsym-(n-octyldibenzo)-16-rown-5-oxymethylphosphonic acid $\underline{2}$ showed better selectivity and alkaline earth metals loading than did the analogous sym-(n-octyldibenzo)-16-crown-5-oxymethyldiphosphonic acid $\underline{6}$.

• Journal of the Korean Applied Science and Technology
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• v.7 no.1
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• pp.49-62
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• 1990

In order to synthesize N,N-di-(polyoxyethylene) perfluoroacyl amines and the surface active monoperfluoroacyl aza crown ethers, it is performed as follow. Six of N,N-di(polyoxyethylene) perfluoro acyl amines were synthesized from perfluoroalkanoic acids with ethanol followed by oxyethylation with triethylene glycol mono chloride or tetra ethylene glycol mono chloride and six of N-perfluor acyl monoaza crown ethers by cyclization of corresponding N,N-di(polyoxy ethylene} perfluoro acyl amines with p-toluene suflonic chloride-NaOH/dioxane, p-toluene sulfonyl chloride KOH/dioxane and benzene sulfonic chloride-KOH/dioxane systems.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.110-113
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• 2003

We report herein synthetic results obtained six new types of bis-benzocrown ethers containing imine group. Bis crown ethers l~3 are aminobenzo-15-crown-5-ether linked with terephthalaldehyde, isophthalaldehyde, phthaldehyde respectively by imine reaction. Bis crown ethers l~3 are different distances in each crown ether rings. Bis crown ether 4 has large cavity in crown ethers. Functionalized crown ether 5 is synthesized amonobenzo-l5-crown-5-ether and terephthaladehyde same ratio at one to one. Bis crown ether 6 has phothosensitive linkage between crown ethers. Bis crown ether 7 is prepared by amonobenzo-l5-crown-5-ether and triethyl ortho formate. 4'-Nitrobenzo-crown ethers and 3',4'-dinitrobenzo-crown ethers were prepared by nitration of benzo crown ethers, obtained from the reaction of catechol and oligoethylene glycol ditosylate. Crown ethers containing aldehyde group were synthesized from the reaction of 3,4-dihydroxybenzaldehyde and corresponding ditosylate respectively. The synthesized crown ethers were characterized respectively by IR, NMR. GC-Mass.