• Bulletin of the Korean Chemical Society
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• 제23권1호
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• pp.132-136
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• 2002

$Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)\;(OTf=CF_3SO_3^-)$ readily reacts with various amines to afford cationic amine complexes $[Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(amine)](OTf)\;(amine=NH_3,\;NHMe_2,\;NHC_4H_8,\;NH_2Ph,\;NH_2(Tol-p))$ in high yields. These complexes have been fully characterized by IR, $^1H-,\;^{19}F{^1H}-,\;and\;^{31}P{^1H}-NMR$ spectroscopy, and elemental analyses. Reaction of $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)$ with acrylonitrile quantitatively produced the ${\pi}$-olefinic complex $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(CH_2=CHCN)](OTf)$ which is only stable in solution in the presence of acrylonitrile. Attempt at isolating this complex in the pure solid state was failed due to partial decomposition into $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)$ The equilibrium constants $(K_{eq}=[Pt(PCP)-(NH_2R)^+][CH_2=CHCN]/[Pt(PCP)(CH_2=CHCN)^+][NH_2R]:\;[Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(CH_2=CHCN)]^++NH_2R{\rightleftarrows}[Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(NH_2R)]^++CH_2=CHCN=Ph,\;p-tolyl)$ were calculated to be 0.28 (for R = Ph) and 3.1 (R = p-tolyl) at $21^{\circ}C$. The relative stability of the ${\sigma}$-donor amine versus the ${\pi}$-olefinic acrylonitrile complex has been found largely dependent upon the amine-basicity $(pK_b)$, implicating that acrylonitrile practically competes with amine in the platinum coordination sphere. On the contrary to the formation of the acrylonitrile complex, no reaction of $Pt(2,6-(Cy_2PCH_2)_2C_6H_3)(OTf)$ with other olefins such as ethylene, styrene and methyl acrylate was observed.

• 폴리머
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• 제39권3호
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• pp.487-492
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• 2015

Palladium(II) 촉매를 이용한 norobornene carboxylic acid estsers의 중합 시 단량체의 알킬 작용기의 종류, endo/exo 비율이 촉매의 활성도 및 중합 특성에 미치는 영향을 조사하였다. Norbornene esters 단량체는 5-norborene-2-carboxylic acid와 다양한 알코올을 반응시켜 합성하였다. 중합 촉매로는 di-$\mu$-chloro-bis(-methoxybicyclo[2,2,1]-hept-2-ene)palladium(II)(DCBMP)를 합성하여 사용하였고, 짝음이온으로 실버 헥사플루오로안티모네이트($AgSbF_6$)를 이용하였다. 고분자의 분석을 위해 젤 투과 크로마토그래피(gel permeation chromatography, GPC), 열 중량 분석법(thermogravimetric analysis, TGA), 시차주사 열량측정법(differential scanning calorimetry, DSC), 화학구조 분석을 위해 $^1H$ NMR spectroscopy를 이용하였다. 분자량 분석 결과 모든 작용기의 경우 endo-이성체의 비율이 exo-이성체의 비율보다 높을 경우 촉매의 구조적 방해로 인하여 반응성이 감소됨을 보였다. 또한 단량체와 촉매의 비율이 중합 거동에 미치는 영향을 조사하기 위해 단량체와 촉매의 몰비율을 100:1, 200:1, 300:1로 변화시켜 실험을 진행하였으며, 이 때 exo-norbornene carboxylic acid octyl ester의 경우 300:1 촉매비에서 필름형성이 가능한 높은 분자량($M_n=27500g/mol$)의 고분자를 합성할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제16권6호
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• pp.524-528
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• 1995

The reaction of [IrCl(cod)]2 with ppol ligand, Ph2PCH2CH2CH2P(Ph)CH2CH2CH=CH2, in ethanol gives an iridium complex, whose structure is converted from an ionic form, [Ir(cod)(ppol)]Cl·2C2H5OH (1),in polar solvents (ethanol, methanol and acetonitrile), to a molecular form, [IrCl(cod)(ppol)], in non-polar solvents (benzene and toluene). The cationic complexes, [Ir(cod)(ppol)]AsF6·1/2C2H5OH and [Ir(cod)(ppol)]PF6·1/2CH3CN, were prepared to compare with the ionic form by 31P NMR spectroscopy. When carbon monoxide is introduced to 1, cod is replaced by CO to give the 5-coordinated complex, [IrCl(CO)(ppol)]. Hydrogenation of 1-octene was not successful in the presence of 1. In order to verify the reason for 1 not behaving as a good catalyst for hydrogenation, electrophilic reactions with HCl, I2 and HBF4·etherate were performed, which yielded the oxidative addition product, [IrHCl2(ppol)], the substitution product, [IrI(cod)(ppol)], and another cationic product, [Ir(cod)(ppol)]BF4, respectively. Thus, the iridium complex is not sufficiently basic to activate hydrogen atoms or the olefin of the ppol ligand.

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.2021-2026
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• 2011

AgNPs (silver nanoparticles) has been widely used for the commercial products, which have antimicrobial agent, medical devices, food industry and cosmetics. Despite, AgNPs have been reported as toxic to the mammalian cell, lung, liver, brain and other organs and many researchers have investigated the toxicity of AgNPs. In this study, we investigated toxicity of the AgNPs to the liver cell using metabolomics based on HRMAS NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Resonance) technics, which could apply to the intact tissues or cells, to avoid the sample destruction. Target profiling and multivariative statistical analysis were performed to analyze the 1D $^1H$ spectrum. The results show that the concentrations of many metabolites were affected by the AgNPs in the liver cell. The concentrations of glutathione (GSH), lactate, taurine, and glycine were decreased and most of amino acids, choline analogues, and pyruvate were increased by the AgNPs. Moreover, the levels of the metabolites were recovered upto similar level of metabolites in the normal cell by the pre-treatment of NAC, external antioxidant. The results suggest that the depletion of the GSH by the AgNPs might induce the conversion of lactate and taurine to the pyruvate.

• 한국식품영양과학회지
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• 제44권7호
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• pp.1090-1099
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• 2015

본 연구는 잠상산물로부터 고부가가치 항당뇨 기능성 소재를 개발하기 위한 연구의 일환으로, 먼저 뽕나무 부위별 4가지(오디, 뽕잎, 상지, 상백피) 에탄올 추출물의 ${\alpha}$-glucosidase 저해활성을 측정한 결과 상백피가 가장 높은 저해활성을 나타내었으며, 그로부터 여러 column chromatography 및 NMR 기기분석을 통해 4가지 ${\alpha}$-glucosidase 저해제를 분리, 정제 및 동정한 결과는 다음과 같다. 상백피 에탄올 추출물을 Diaion HP-20, silica gel, ODS-A 및 Sephadex LH-20 column chromatography를 실시하여 4가지 화합물[Comp. 1(10 mg), Comp. 2(9.6 mg), Comp. 3(9.3 mg), 및 Comp. 4(6.5 mg)]을 분리 및 정제하였으며, 그들의 효소 저해활성을 측정한 결과 Comp. 1($IC_{50}=5.22{\mu}g/mL$), Comp. 2($IC_{50}=1.78{\mu}g/mL$), Comp. 3($IC_{50}=2.94{\mu}g/mL$) 및 Comp. 4($IC_{50}=1.54{\mu}g/mL$)로 나타났다. 그리고 그들 화합물의 동정을 위해 UV 및 NMR spectroscopy를 이용하여 구조를 분석한 결과 Comp. 1(morusin), Comp. 2(kuwanon H), Comp. 3(chalcomoracin A), Comp. 4(chalcomoracin B)로 각각 동정하였다. 이상의 연구 결과로 미루어 보아 상백피로부터 분리된 ${\alpha}$-glucosidase 저해제는 향후 당뇨 치료용 기능성 소재로 활용할 수 있을 것으로 기대된다.

• Macromolecular Research
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• 제17권10호
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• pp.770-775
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• 2009

$\omega$-Anhydride-functionalized poly(ethylene oxide) (PEO) obtained from chain-end functionalization and anionic ring-opening polymerization of ethylene oxide using n-butyllithium with potassium t-butoxide in the presence of dimethylsulfoxide (DMSO) was found to be an efficient material for the preparation of water-soluble, polymeric pro-drugs. The reaction of $\omega$-anhydride-functionalized PEO with sulfonamide or with vancomycin provided an efficient method to produce corresponding, water-soluble, PEO-conjugated sulfonamide or PEO-conjugated, vancomycin pro-drugs. These were used successfully to prepare water-dispersible, silver nanoparticles. In this study, the particle sizes were in the range of $5{\sim}40$ nm. The resulting products were characterized by $^1H$ NMR spectroscopy, transmission electron microscopy, electron and X-ray diffraction, size exclusion chromatography, and UV/Visible spectroscopy.

• Macromolecular Research
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• 제17권5호
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• pp.301-306
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• 2009

This work has demonstrated that a novel amphiphilic poly(epichlorohydrine)-graft-polystyrene (PECH-g-PS) copolymer at 34:66 wt% was synthesized via atom transfer radical polymerization (ATRP) of styrene using PECH as a macroinitiator. The structure of the graft copolymer was characterized by nuclear magnetic resonance ($^1H$ NMR) and FTIR spectroscopy, demonstrating that the "grafting from" method using ATRP was successful. The self-assembled graft copolymer was used as a template film for the in-situ growth of silver nanoparticles from $AgCF_3SO_3$ precursor under UV irradiation. The in situ formation of silver nanoparticles with 6-8 nm in average size in the solid state template film was confirmed by transmission electron microscopy (TEM), UV-visible spectroscopy and wide angle X-ray scattering (WAXS). Differential scanning calorimetry (DSC) also displayed the selective incorporation and the in situ formation of silver nanoparticles within the hydrophilic PECH domains, probably due to stronger interaction of the silvers with the ether oxygens of PECH backbone than that with hydrophobic PS side chains.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2249-2252
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• 2011

Two new carborane complexes containing closo- or nido-carborane diphosphine ligands with the formula: complex $[Hg(7,8-(PPh_2)_2-7,8-C_2B_9H_{10})_2]$ $CH_2Cl_2$ (1) and $[Ag_2({\mu}-Cl)_2(1,2-(P^iPr_2)_2-1,2-C_2B_{10}H_{10})_2]$ (2) have been synthesized and characterized by elemental analysis, 1H and 13C NMR spectroscopy and X-ray structure determination. The X-ray structure analyses revealed that the carborane diphosphine ligand was degraded from closo-1,2-$(PPh_2)_2-1,2-C_2B_{10}H_{10}$ to nido-[$7,8-(PPh_2)_2-7,8-C_2B_9H_{10}]^-$ in complex 1, while the closo nature of the starting ligand $1,2-(P^iPr_2)_2-1,2-C_2B_{10}H_{10}$ was retained in complex 2. In either of the two complexes, the carborane diphosphine ligand was coordinated bidentately to the Hg(II) or Ag(I) center through its two phosphorus atoms, therefore forming a five-member cheating ring between the carborane ligand and the metal center. The coordination geometry of the metal atom is distorted tetrahedron formed by $P_4$ unit in complex 1 and $P_2Cl_2$ unit in complex 2, respectively.

• 한국응용과학기술학회지
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• 제38권2호
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• pp.476-487
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• 2021

고형분 70% 아크릴수지를 합성하기 위해 n-butyl methacrylate(BMA), methyl methacrylate(MMA), 2-hydroxyethyl methacrylate(2-HEMA) 및 acetoacetoxyethyl acrylate(AAEA)와 caprolactone acrylate(CLA)를 사용하여 공중합체의 유리전이온도(T_g)를 50 ℃로 조정하여 합성하였으며, 합성한 아크릴수지의 점도와 분자량은 수산기가(OH values)의 증가에 따라 증가되었다. 높은 고형분의 아크릴수지 합성에 적합한 반응개시제는 di-tert-amyl peroxide 이었으며, 최적의 합성조건은 반응 개시제 5 wt%, 연쇄이동제 4 wt%, 반응온도 140 ℃에서 적하시간은 4시간이었다. 합성수지의 구조는 FT-IR과 ¹H-NMR spectroscopy로 확인하였고, 수평균 분자량은 1900~2600, 분자량 분포도 1.4~2.1을 얻었다. 합성한 아크릴수지와 무황변성 폴리이소시아네이트인 hexamethylene diisocyanate trimer(Desmodur N-3300)의 NCO/OH 당량비를 1.2/1.0으로 조절하여 아크릴-우레탄 투명도료를 제조하였다. 도료의 물리적 특성으로 점도, 부착성, 건조시간, 가사시간, 연필경도 및 광택을 비교 검토한 결과 부착성, 건조시간, 가사시간, 연필경도 및 광택이 양호한 결과를 나타내었고, 특히 CLA를 10 % 도입한 도료는 부착성이 우수하고 낮은 점도와 높은 경도를 나타내었다.

• 대한화학회지
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• 제42권2호
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• pp.184-189
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• 1998

Indium(III) trihalides (halogen=Cl, Br)와 bis(pentafluorophenyl)cadmiumd을 acetonitrile에서 반응시켜 acetonitrile이 배위된 tris(pentafluorophenyl)indium을 합성하였으며 원소분석, 핵자기 공명과 질량분석 스펙트럼을 이용하여 특성을 조사하였다. 그 결과 acetonitrile과 배위한 tris(pentafluorophenyl)indium는 pentafluorophenylindium화합물과 acetonitrile이 1:1로 배위된다는 것을 알 수 있었다. 또한 In$(C_6F_5)_3{\cdot} CH_3CN$과 DMAP(dimethylaminopyridine)를 dichloro methane 용매에서 리간드를 치환반응시켜 In$In(C_6F_5)_3{\cdot}DMAP$를 합성하였다. 리간드들의 치환은 acetonitrile보다 주개 성질이 강한 DMAP가 acetonitrile의 자리에 배위하는 것으로 생각된다.