• 분석과학
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• 제6권5호
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• pp.417-424
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• 1993

5,7-디클로로-8-히드록시퀴놀리놀(Hdcq)과 2-메르캅토피리미딘(Hmpd)를 포함하는 8-배위 테트라키스 몰리브데늄(IV) 착물을 합성하였다. $Mo(mpd)_4$, $Mo(dcq)(mpd)_3$, $Mo(dcq)_2(mpd)_2$, $Mo(dcq)_3(mpd)$와 $Mo(dcq)_4$ 착물들을 TLC plate에서 분리하였다. 이 착물들의 특성을 $^1H-nmr$ 스펙트럼과 자외선-가시광선 스펙트럼으로 조사하였다. 리간드의 질소원자에 대한 ${\alpha}$위치 양성자의 화학적 이동값은 낮은 장으로 이동되었으며, $Mo(dcq)(mpd)_3$와 $Mo(dcq)_3(mpd)$는 같은 위치의 양성자가 2:1의 상대적 세기로 나타났고 $Mo(dcq)_2(mpd)_2$는 거의 같은 세기였다. 이들 착물의 입체화학을 nmr 스펙트럼과 Orgel 규칙으로 고찰했다. 이 착물들의 전자전이 스펙트럼은 세기(${\varepsilon}$>10,000~25,000)와 낮은 에너지($16,600{\sim}19,800cm^{-1}$) 흡수띠를 관찰하여 이를 전하이동 흡수띠로 해석하였다.

• 한국자기공명학회논문지
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• 제9권2호
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• pp.103-109
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• 2005

New PVC plasticizer, 2,2,4-trimethyl-1,3-pentanediol-1-butyrate-3-isobutyrate was synthesized via simple esterification with butyric acid and Texanol(a trademark of Eastman Chemicals), the mixture of 2,2,4-trimethyl-1,3-pentanediol-3-isobutyrate and 2,2,4-trimethyl-1,3-pentanediol-1-isobutyrate. The analysis of $^1H-1D,\;^{13}C-1D$ NMR and HMBC spectra identified internal-ester-transfer of 2,2,4-trimethyl-1,3-pentanediol-1-isobutyrate during the reaction. 2,2,4-trimethyl-1,3-pentanediol-1-butyrate-3-isobutyrate gave better properties in PVC than 2,2,4-trimethyl-1,3-pentanediol diisobutyrate(TXIB, a trademark of Eastman Chemicals) such as lower viscosity, higher tensile strength and better elongation. In particular, remarkably reduced migration compared with TXIB suggested a reduced emission of VOC(volatile organic compound) from PVC.

• Natural Product Sciences
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• 제22권1호
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• pp.30-34
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• 2016

A simple and rapid method based on proton nuclear magnetic resonance spectroscopy was developed for determination of trans-anethole content in fennel essential oil. Spectra of pure trans-anethole, of the pure essential oil of fennel, and of the pure oil of fennel with thymol internal standard were recorded. The signal of $H-1^/$ was used for quantification of trans-anethole. This proton signal is well separated in the proton magnetic resonance spectrum of the compound. No reference compound is needed and cheap internal standard was used. The results obtained from spectroscopic analysis were compared with those obtained by gas chromatography. Additionally, the developed method was used for determination of the type of vegetable oil used as a carrier in commercial products, which cannot be quantified as such by gas chromatography. This study demonstrates the application of proton nuclear magnetic resonance spectroscopy as a quality control method for estimation of essential oil components.

• Bulletin of the Korean Chemical Society
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• 제11권6호
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• pp.531-534
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• 1990

The reaction of $Os_3(CO)_{10}(NCMe)_2$ with a tungsten alkylidyne $Cp(CO)_2W{\equiv}CTol(Cp={\eta}^5-C_5H_5,\;Tol=p-C_6H_4Me)$ produces the compound, $CpWOs_3(CO)_{11}({\mu}_3-CTol)$(1). The structure of compound 1 can be viewed as one in which the metalla-alkyne, $Cp(CO)_2W{\equiv}CTol$, is ${\mu}_3-{\eta}^2-{\bot}$ (perpendicular) bound to an $Os_3(CO)_9$ fragment. Variable-temperature $^{13}C$ NMR spectra of 1 show no evidence for the analogous rotation of the metalla-alkyne molecule as shown alkyne rotation in $Os_3(CO)_9(C_2Tol_2)$ compound. This lack of the metalla-alkyne fluxionality supports the apparent saturated nature of compound 1.

• Journal of Gastric Cancer
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• 제3권3호
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• pp.151-157
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• 2003

Purpose: In this study, we attempted to ascertain the proton magnetic resonance spectroscopy (${1}^H$ MRS) peak characteristics of human gastric tissue layers and finally to use the metabolic peaks of MRS to distinguish between normal and abnormal gastric specimens. Materials and Methods: Ex-vivo ${1}^H$ MRS examinations of thirty-five gastric specimens were performed to distinguish abnormal gastric tissues invaded by carcinoma cells from normal stomach-wall tissues. High-resolution 400-MHz (9.4-T) ${1}^H$ nuclear magnetic resonance (NMR) spectra of two gastric layers, a proper muscle layer, and a composite mucosasubmucosa layer were compared with those of clinical 64- MHz (1.5-T) MR spectra. Three-dimensional spoiled gradient recalled (SPGR) images were used to determine the size and the position of a voxel for MRS data collection. Results: For normal gastric tissue layers, the metabolite peaks of 400-MHz ${1}^H$ MRS were primarily found to be as follows: lipids at 0.9 ppm and 1.3 ppm; alanine at 1.58 ppm; N-acetyl neuraminic acid (sialic acid) at 2.03 ppm; and glutathione at 2.25 ppm in common. The broad and featureless featureless spectral peaks of the 64-MHz MRS were bunched near 0.9, 1.3, and 2.0, and 2.2 ppm in human specimens without respect to layers. In a specimen (Borrmmann type III) with a tubular adenocarcinoma, the resonance peaks were measured at 1.26, 1.36 and 3.22 ppm. All the peak intensities of the spectrum of the normal gastric tissue were reduced, but for gastric tumor tissue layers, the lactate peak split into 1.26 and 1.39 ppm, and the peak intensity of choline at 3.21 ppm was increased. Conclusion: We found that decreasing lipids, an increasing lactate peak that split into two peaks, 1.26 ppm and 1.36 ppm, and an increasing choline peak at 3.22 ppm were markers of tumor invasion into the gastric tissue layers. This study implies that MR spectroscopy can be a useful diagnostic tool for gastric cancer.

• 대한화학회지
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• 제39권11호
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• pp.856-862
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• 1995

본 연구의 텅스텐 옥소-니트로실 착물 $(n-Bu_4N)_2[W_5O_{12}(NO)_2{RC(NH_2)NHO}_2{RC(NH)NO}_2]{R\;=\;(CH_3)CH, CH_3CH_2CH_2,CH_3SCH_2}$은 텅스텐(VI) 다핵 착물 $(n-Bu_4N)_2[W_6O_{19}]$, 텅스텐 디니트로실 단핵 착물 $[W(NO)_2(acac)(CH_3CN)_2](BF_4)$ 및 부틸 아미드옥심 유도체의 반응에서 얻었다. 합성한 착물은 원소분석, 적외선, 전자 흡수 및 핵자기 공명 스펙트럼에 의해 특성을 조사하였다. 전자를 끌어당기는 ${W(NO)_2}^{2+}$ 단위체는 두 개의 이핵체 ${W_2O_5}^{2+}$ 사이의 중심에 삽입되어 오핵종을 이룬다. $(n-Bu_4N)_2[W_5O_{12}(NO)_2{(CH_3)_2CHC(NH_2)NHO}_2/{(CH_3)_2/CHC(NH)NO}_2]$의 $^1{H} NMR$ 스펙트럼에서 네 개의 이중선이 나타남으로 양성자간의 상호작용이 큰 것을 추정할수있다. $^{13}C$ NMR 스펙트럼은 배위된 네 개의 배위자중 두개의 배위자가 나타남으로 두 배위자의 서로 다른 배위모형과 대칭성에 대한 정보를 준다. ${W(NO_2)}^{2+}$ 단위체는 형식상 시스형이며 기하학적으로 $C_{2v}$ 대칭을 가진다.

• 대한화학회지
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• 제39권3호
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• pp.198-203
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• 1995

두 개 산소가교형의 $[Mo_2O_4(H_2O)_6]_2^+$와 디티오 디카르복시기를 가진 리간드를 반응시켜 $Mo_2O_4(H_2O)_2L(L:\;C_3H_7CH(SCH_2COOH)_2,\;C_6H_5CH(SCH_2COOH)_2,\;CH_3OC_6H_4CH(SCH_2COOH)_2,\;C_5H_{10}C(SCH_2COOH)_2,\;C_3H_7C(CH_3)(SCH_2COOH)_2,\;C_3H_7CH(SCH_2CH_2COOH)_2,\;C_6H_5CH(SCH_2CH_2COOH)_2)$형의 착물을 합성하고 이들 착물의 구조를 분광학적인 방법(IR, $^1H$ NMR, UV-Visible)으로 그 구조를 규명한 결과 한 개의 리간드가 두 몰리브덴 금속에 킬레이트형으로 결합되며 말단 산소간에는 트란스형을 유지하고 있으며 이들 각 말단산소의 트란스에 $H_2O$가 한 개씩 배위되어 있다. 이들 착물들의 산화 환원전위값을 순환 전압전류법으로 수용액상에서 측정한 결과 환원전위는 -0.50∼-0.58 V(vs. SCE) 사이, 산화전위는 -0.41∼-0.43 V(vs. SCE) 사이에서 나타나며 이들 산화-환원 전류비 값이 거의 1에 가깝고 전위차이 값이 0.10 V 정도인 것으로 보아 두 개 산소 가교형의 기본 골격이 유지되는 가역적인 산화-환원 반응으로 추정된다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1997년도 춘계학술대회
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• pp.86-86
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• 1997

Human annexin I is a member of annexin family of calcium dependent phospholipid binding proteins, which have been implicated in various physiological roles including phospholipase A$_2$ (PLA$_2$) inhibition, membrane fusion and calcium channel activity. In this work, the structure of N-terminally truncated human annexin I (Δ-annexin I) and its interactions with Ca$\^$2+/, ATP and cAMP were studied at atomic level by using $^1$H, $\^$15/N, $\^$l3/C NMR (nuclear magnetic resonance) spectroscopy. The effect of Ca$\^$2+/ binding on the structure of Δ-annexin I was investigated, and compared with that of Mg$\^$2+/ binding. The addition of Ca$\^$2+/ to Δ-annexin I caused some changes in the high field and low field regions of $^1$H NMR spectra. Whereas, upon addition of Mg$\^$2+/ to Δ-annexin I, almost no change could be observed. Also we found that the binding ratio of ATP to Δ-annexin I is 1. Because Δ-annexin I is a large protein with 35 kDa molecular weight, site-specific (carbonyl-$\^$l3/C, amide-$\^$15/N) labeling technique was used to determine the interaction sites of Δ-annexin I with Ca$\^$2+/ and ATP. Assignments of all the histidinyl carbonyl carbon resonances have been completed by using Δ-annexin I along with its specific 1,2-subdomain. The carbonyl carbon resonances originating from His52 and His246 of Δ-annexin I were significantly affected by Ca$\^$2+/ binding, and some Tyr and Phe resonances were also affected. The carbonyl carbon resonances originating from His52 is significantly affected by ATP binding, therefore His52 seems to be involved in the ATP binding site of Δ-annexin I.

• 대한화학회지
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• 제55권4호
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• pp.612-619
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• 2011

1,2-diphenyl-4-butyl-3,5-pyrazolidinedione(phenylbutazone, PB)의 란탄(III) 착물을 합성하여 원소분석, 몰전기전도도 측정, IR, UV-Vis. 및 NMR 스펙트럼으로 특성을 조사하였다. 스펙트럼 데이터로부터 PB가 pyrazolidinedione 고리의 두 카르보닐 산소를 통해 이배위 및 일이온화 리간드로 배위됨을 규명하였다. 몰전기전도도 데이터로부터 이들 착물이 비전해질임을 규명하였다. 이들 착물의 열적 행동을 공기 중에서 TG 및 DTG로 연구한 결과, 탈수화, 열적 안전성 및 열분해에 관한 정보를 얻을 수 있었다. 최종 생성물은 해당 금속의 산화물로 밝혀졌다. 탈수화 및 분해 단계에 대한 열역학 및 반응속도 파라메터를 구하였다. 분해 단계에 대한 음의 엔트로피 값은 반응물보다 활성화 착물이 더 질서있는 구조를 갖는다는 것을 의미하며, 이때 반응은 정상보다 느렸다. 이러한 연구를 바탕으로 착물의 분자식이 $[Ln(PB)_3]{\cdot}5H_2O$(Ln=La 및 Ce) 그리고 $[Ln(PB)_3 (H_2O)_2]{\cdot}2H_2O$(Ln=Pr, Nd 및 Sm)임을 규명하였다.

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.761-766
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• 2008

Photoresponsive arylether dendrimers Bis-azo-Gn(3,5) 1a-1c and Bis-azo-Gn(3,4,5) 2a-2c (n = 1-3) with an azobenzene unit at the core and several vinyl groups (3,5-bis(but-3-enyloxy)phenyl groups or 3,4,5-tris(but-3- enyloxy)phenyl groups) at the periphery have been prepared. Their structures and reversible trans-cis isomerization behaviors have been investigated by $^1H$-NMR, $^{13}C$-NMR, MALDI-TOF-Mass, and UV-vis spectra. All six azobenzene-cored dendrimers carried out very fast trans $\rightarrow$ cis photoisomerization on irradiation of 350 nm light and reached to the photostationary state within 180 s. During the dark incubation, slow thermal back reversion from cis to trans form is observed for all six dendrimers and is completed within 3 days for 1a-1c and 1 day for 2a-2c. Isomerization efficiency decreases with increasing generation. However, the initial reaction rates of both trans $\rightarrow$ cis photochemical isomerization and cis $\rightarrow$ trans thermal isomerization increases significantly with increasing generation for dendrimers for 1a-1c but only slightly for 2a-2c.