• Macromolecular Research
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• 제12권3호
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• pp.258-262
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• 2004

We have developed facile and rapid polycondensation reactions of N-trimellitylimido-L-leucine diacid chloride 1 with eight different derivatives of hydantoin compounds 2a-h, in the presence of a small amount of a polar organic medium, such as Ο-cresol, by using a domestic microwave oven. The polycondensation reactions proceeded rapidly-they were complete within 7-9 min-to produce a series of novel optically active poly(amide-imide)s (3a-h) in high yield with inherent viscosities of 0.33-0.51 dL/g. We characterized the resulting poly(amide-imide)s by elemental analysis, thermal gravimetric analysis (DSC, TGA, and DTG), and FTIR spectroscopy, and by measuring their viscosities, specific rotations, and solubilities. All of the polymers were soluble at room temperature in polar solvents such as N ,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, tetrahydrofuran, and N-methyl-2-pyrrolidone.

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1751-1756
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• 2003

An electrochemical study related to the electroreduction of 4-amino-6-methyl-3-thio-1,2,4-triazin-5-one(I), 6-methyl-3-thio-1,2,4-triazin-5-one(II), and 2,4-dimetoxy-6-methyl-1,3,5-triazine(III) in dimethylformamide at glassy carbon electrode has been performed. A variety of electrochemical techniques, such as differential pulse voltammetry (DPV), cyclic voltammetry (CV), chronoamperometry, and coulometry were employed to clarify the mechanism of the electrode process. The compounds I and II with thiol group exhibited similar redox behavior. Both displayed two cathodic peaks, whereas the third compound, III, without thiol group showed only one cathodic peak in the same potential range of the second peak of I and II. The results of this study suggest that in the first step the one electron reduction of thiol produced a disulfide derivative and in the second reduction step the azomethane in the triazine ring was reduced in two electron processes. A reduction mechanism for all three compounds is proposed on this basis. In addition, some numerical constants, such as diffusion constant, transfer coefficient, and rate constant of coupled chemical reaction in the first reduction peak were also reported.

• Korean Chemical Engineering Research
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• 제61권2호
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• pp.322-327
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• 2023

A design of experiments was evaluated in optimizing MOF-5 synthesis for acetylene adsorption. At first, mixture design was used to optimize precursor concentration, terephthalic acid, zinc acetate dihydrate and N,N-dimethylformamide. More specifically, 13 conditions with various molar ratios were designed by extreme vertices design method. After preparing the samples, XRD, N₂ physisorption and SEM analysis were performed for their characterization. Moreover, acetylene adsorption experiments were carried out over the samples under identical conditions. The optimal precursor composition for MOF-5 synthesis was predicted on a molar basis as follows: terephthalic acid : acetate dihydrate : dimethylformamide = 0.1 : 0.4 : 0.5. Thereafter, multi-level factorial design was designated to investigate the effect of synthesis reaction conditions such as temperature, time and stirring speed. By the statistical analysis of 18 samples designed, 4 reaction parameters were determined for additional adsorption experiments. Therefore, MOF-5 prepared under the synthesis time and temperature of 100 ℃ and 12 h, respectively, showed the maximum adsorption capacity of 15.1 mmol/g.

• 통합자연과학논문집
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• 제8권4호
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• pp.235-243
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• 2015

Rhodium(I)-complex of $[Rh(CO)_2I_2{^-}]$ catalyzed carbonylation of anhydrous-trimethylamine in the presence of methyl iodide to give DMAC (N,N-dimethylacetamide) in no solvent. The catalyst had been reused 20 times, the analyses and distillation of collected products showed that the yields of DMAC, MAA (N-methylacetamide), and DMF (N,N-dimethylformamide) were 82.3%, 12.6%, and 4.4%. The conversion rate of trimethylamine was 99 % and the selectivity of DMAC was 82.3% with TON (Turnover Number) of 700. Stepwise procedure of inner-sphere reductive elimination for the formation of DMAC was suggested instead of acyl iodide intermediate.

• Macromolecular Research
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• 제13권1호
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• pp.14-18
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• 2005

Under irradiation in a microwave oven, six novel poly(amide-imide)s containing tetrahydropyrimidinone, tetrahydro-2-thioxopyrimidine moieties and trimellitic rings in their main chains were synthesized through the polycondensation reaction of N,N'-(4,4'-diphenylether)bis(trimellitimide) diacid chloride with six different derivatives of tetrahydropyrimidinone and tetrahydro-2-thioxopyrimidine in the presence of a small amount of a polar organic medium, such as o-cresol. The polycondensation proceeded rapidly and completed within 7-9 min, producing a series of new poly(amide-imide)s in high yield that showed inherent viscosities in the range 0.33-0.52 dL/g. These poly(amide-imide)s were characterized by elemental analysis, viscosity measurement, thermal gravimetric analysis, solubility test, and FT-IR spectroscopy. All of the polymers were soluble at room temperature in polar solvents such as N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, tetrahydrofuran, and N-methyl-2-pyrrolidone.

• 폴리머
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• 제36권4호
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• pp.427-433
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• 2012

이미드/아라미드/설폰기가 교대로 도입된 poly(imide-aramid-sulfone)s을 divinyl sulfone(DVS)과 $N^1,N^4$-bis(4-(vinylsulfonyl)phenyl)terephthalamide (2)를 pyromellitic diimide와 반응하여 높은 수율로 제조하였다. 또한 고분자를 닮은 3가지 모델 화합물인 N-[2-(p-aminophnenylsulfonyl)ethyl]phthalimide (3), 2,2'-(2,2'-sulfonylbis(ethane-2,1-diyl))diisoindoline-1,3-dione (4), 및 N,N-bis(4-(2-(1,3-dioxoisoindolin-2-yl)ethylsulfonyl)phenyl)terephthalamide (5)을p-aminophenyl vinyl sulfone, DVS, 2와 phthalimide와 반응하여 얻었다. 축합 중합은 phthalimide 기와 DVS의 마이클 첨가 반응에 의하여 균일 용액으로 진행되며 tetrabutylammonium hydroxide (TBAH)가 촉매로 작용하여 poly(imide-aramid-sulfone)s 6-12의 분자량이 큰 중합체를 얻을 수 있었다. DVS/2의 구성비는 1/0, 3/1, 2/1, 1/1, 1/2, 1/3, 및 0/1이다. 얻어진 고분자들은 극성 용매인 N,N-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidinone 및 tetrahydrofuran에 잘 용해하였다. 그 밖에 분자량, 점도 그리고 열적 성질을 평가하였다.

• 한국환경농학회지
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• 제33권4호
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• pp.344-349
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• 2014

BACKGROUND: Purpose of the study was to establish the extinction coefficients of chlorophyll a and b in N,N-dimethylformamide(DMF) and Dimethylsulfoxide(DMSO) solvents and to find out the conditions of optimal extraction temperature and time in citrus leaves. METHODS AND RESULTS: Chlorophyll a and b standards were dissolved in DMF and DMSO. Extinction coefficients of chlorophyll pigments were determined and their contents were quantified using spectrophotometer. Chlorophyllous pigments of citrus(Citrus unshiu Marc. cv. Okitsu wase) leaves were extracted at 25, 40, 60 and $80^{\circ}C$ for 4, 6, 8, 24 and 48 hours to determine the optimal extraction condition. CONCLUSION: The extinction coefficients of chlorophyll a(Chl a) and chlorophyll b(Chl b) of DMF extracts for high extinction wavelength were 663.8 and 647.2 nm. Similarly, the high extinction wavelength of DMSO extracts were 665.8 and 649.0 nm for chl a and b respectively. Chl a, Chl b and total chlorophyll content of DMF extracts were Chl a = $12.10A_{663.8}-2.74A_{647.2}$, Chl b = $21.94A_{647.2}-5.06A_{663.8}$ and total $Chl=19.193A_{647.2}+7.04A_{663.8}$. Similarly, Chl a, Chl b and total Chl of DMSO extracts were Chl a = $14.53A_{665.8}-5.40A_{649.0}$, Chl b = $26.98A_{649.0}-7.11A_{665.8}$ and total $Chl=21.58A_{649.0}+7.43A_{665.8}$. The chlorophyll extracts of DMF and DMSO were very stable in dark. High chlorophyll contents of citrus leaves were found at $80^{\circ}C$ extraction for 6 hours in DMF and at $80^{\circ}C$ extraction for 24 hours in DMSO. However, the chlorophyll content was decreased significantly after 8 hours in DMF extraction while it was remained up to 30 hours in DMSO extraction.

• 한국환경보건학회지
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• 제23권1호
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• pp.62-65
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• 1997

The insecticidal and antibacterial activity of new synthesized carbamate derivatives(5,7-dibromo-8-hydroxyquinolinyl-N-methylcarbamate(I), 5,7-dibromo-8-hydroxyquinolinyl-N-ethylcarbamate(II)) was examined using 0.2w/v% acetone solutions and 50 $\mu$g/ml-1000 $\mu$g/ml N,N'-dimethylformamide H$_2$O(2:3) solutions of each compounds, respectively. 1. Two carbamates exerted insectiddal effects on Sogata furcifera HORVATH, Delphacodes Striatella FAUEN and Nilaparvate lugens STAL, Whereas no significant effects were observed on the Inazuma dorasalis MOISCHIULSKY Nephateffix apicalis Cincticeps UHLER. 2. These compounds exhibited growth-inhibitory activity against Staphyloccus aureus, Salmonella paratyphi A, Shigella dysenteriae 1a, Escherichia coli NL 1401, at the concentration range of 100-500 $\mu$g/ml in general.

• 한국환경보건학회지
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• 제21권1호
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• pp.74-77
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• 1995

The insecticidal and antibacterial activity of new synthesized carbamate derivatives(8-Hydroxy-5-chloroquinolyl-N-methylcarbamate(I), 8-Hydroxy-5-chloroquinolyl-N-ethylcarbamate(II)) was examined using 0.2 w/v% acetone solutiolas and 50 r/ml~1000 r/m N,N'-dimethylformamide-$H_2O$(2:3) solutions of each compounds, respectively. 1) Two carbamates exerted insecticidal effects on Sogata furcifera HORVATH, Delphacodes Striatella FAUEN, Whereas no significant effects were observed on the Nilaparvate lugens STAL, Inazuma dorasails MOISCHIULSKY and Nephateffix apicalis Cincticeps UHLER. 2) These compounds exhibited growth-inhibitory activity against Staphylococcus aureus, Salmonella paratyphi A, Shigella dysenteriae 1a, Escherichia coli NL 1401,at the concentration range of 100~500 r/ml in general.

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1537-1540
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• 2013