• Bulletin of the Korean Chemical Society
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• 제16권6호
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• pp.528-533
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• 1995

Metallic iridium and rhodium powders prepared from the reactions of [M(COD)(PhCN)2]ClO4 (M=Ir(1), Rh(2); COD=1,5-cyclooctadiene) with hydrogen at room temperature in methylene chloride show catalytic activities for hydrogenation of arenes at room temperature under atmospheric pressure of hydrogen. Most substituents (CH3, COOH, NO2, CH2OH, CHO, OPh, OCH3, C=C, halogens and CH2Cl) on aromatic ring suppress the rate of the hydrogenation of the aromatic ring while the aromatic ring hydrogenation of phenol and 1,4-dihydroxobenzene is faster than that of benzene over these metallic powders. Hydrogenation of benzoic acid occurs only at the aromatic ring leaving the COOH group intact over iridium metal powders while benzoic acid is not hydrogenated at all over rhodium metal powders. Carbonyl, nitro, acetylenic and olefinic groups on an aromatic ring are hydrogenated prior to the aromatic ring hydrogenation. Hydrogenolysis of OH groups of phenol, benzyl alcohol and 1,4-dihydroxobenzene, and hydrodehalogenation of halobenzenes, benzyl halides and cinnamyl chloride also occur along with the hydrogenation of aromatic ring.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2737-2742
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• 2011

Ring-opening metathesis polymerization (ROMP) of an ethyl-substituted tetracyclododecene (8-ethyltetracyclo[$4.4.0.1^{2,5}.1^{7,10}$] dodec-3-ene, Et-TCD) was carried out in the presence of a ternary catalyst system consisting of $WCl_6$, triisobutyl aluminium (iso$Bu_3Al$), and ethanol. The optimal molar ratio of Et-TCD/$WCl_3$/iso-$Bu_3Al$/ethanol was found as 500/1/3/2 at which the yield of ring-opened polymer was 100%. 1-Hexene was shown to be an effective molecular weight controlling agent for ROMP reaction of Et-TCD. The hydrogenation of the ring opened polymer (p-Et-TCD) was conducted successfully using Pd(5 wt %)/${\gamma}$-$Al_2O_3$ at $80^{\circ}C$ for 1 h. Chemical structures of p-Et-TCD and its hydrogenated product($H_2$-p-Et-TCD) were characterized using 2D NMR techniques ($^1H-^1H$ COSY and $^1H-^{13}C$ HSQC). The changes of physical properties such as thermal stability, glass transition temperature and light transmittance after the hydrogenation were also investigated using TGA, DSC, and UV.

• Bulletin of the Korean Chemical Society
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• 제35권4호
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• pp.1117-1120
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• 2014

Ru/C-catalyzed hydrogenation of m-xylylene diamine into 1,3-cyclohexanebis(methylamine) was greatly accelerated by the presence of $LiNO_3$, $NaNO_2$, or $NaNO_3$. It was found that the effect of the nitrate salt was significantly affected by the size of cation. The promoting effect of the nitrate salt increased with the decrease of the cation size: $LiNO_3$ ~ $NaNO_2$ > $KNO_3$ > $CsNO_3$ >> [1-butyl-3-methylimidazolium]$NO_3$. XRD analysis of the recovered catalysts after the hydrogenation reactions showed that $LiNO_3$ and $NaNO_2$ were completely transformed into LiOH and NaOH, respectively, along with the evolution of $NH_3$, while $KNO_3$ and $CsNO_3$ remained unchanged.

• Bulletin of the Korean Chemical Society
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• 제9권3호
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• pp.129-132
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• 1988

The stereochemistry of N-acyliminium cyclizations to form decahydropyrrolo[2,1-a]isoquinolin-3(2H)-ones was studied. Particular attention was paid to the stereocontrol by an acetoxy group present on pyrrolidone ring. Two of the three new chiral centers were formed stereospecifically, and the third was controlled by elimination-hydrogenation sequence.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.2949-2954
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• 2011

This paper describes a concise and efficient synthetic route for the biologically interesting pyranoxanthones, dihydropyranoxanthones, and their derivatives. The key strategies involve pyranyl ring formation, methylation, catalytic hydrogenation, and catalytic dihydroxylation starting from 1,3-dihydroxyxanthen-9-one.

• 청정기술
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• 제28권4호
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• pp.331-338
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• 2022

본 연구의 목적은 열분해연료유(pyrolysis fuel oil, PFO)에 포함된 다환 방향족 탄화수소(polycyclic aromatic hydro, PAHs) 수소화 반응용 촉매로서 Pt(1wt%)/Kieselguhr 비드 촉매 및 펠렛 촉매를 제조하는 것이다. Trickle-bed 반응기에서 PFO-cut 수소화 반응을 통한 포화 고리 화합물(saturated cyclic compound)의 수율을 최대화하기 위한 최적의 반응 온도 및 수소/PFO-cut 유량비는 각각 250℃와 1800으로 결정하였다. PFO-cut의 공간속도(LHSV)가 감소할수록 포화 고리 화합물의 수율이 증가하였다. 펠렛 촉매와 비드 촉매의 수소화 반응 성능 차이는 크지 않았다. Kieselguhr 지지체를 성형한 후에 Pt를 담지한 촉매(AI 촉매)가 kieselguhr 분말에 Pt를 담지한 후에 성형한 촉매(BI 촉매)에 비해 수소화 활성이 높았으며, 이러한 경향은 펠릿 촉매와 비드 촉매에서 공통적으로 나타났다. 이는 AI 촉매의 Pt 활성점 수가 BI 촉매 보다 많기 때문이다. 본 연구에서 제조한 촉매 중에서 AI법으로 제조된 펠렛 촉매가 제조된 촉매 중 반응 활성이 가장 우수한 것을 확인하였다. PFO-cut 수소화 반응 생성물 중 C₈~C₁₅ 범위의 고리 화합물이 대부분을 차지했으며, C11 고리 화합물의 분포도가 가장 높았다. 수소화 반응과 더불어서 분해 반응도 함께 촉진되어 생성물의 탄소수 분포가 경질 탄화수소 쪽으로 이동함을 확인하였다.

• Tribology and Lubricants
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• 제8권1호
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• pp.56-62
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• 1992

The naphthenic base oil has been formulated to insulating and refrigerating oils. In the views of decreasing of the naphthenic crtide oil, new sources as its replacement have been needed. To solve this situation, the synthesis of naphthenic oil has been carried under hydrogenation reactions of alkyl aromatic compounds using various catalysts. The sturcture of reaction products has been investigated using spectroscopic methods such as NMR, UV, IR and HPLC. On the basis of the experimental results, it was convinced that unsaturated aromatic ring was saturated to saturated rings, and also optimum cond~tions established. Throughout this study, new resource as the replacement of conventional naphthenic oil has introduced.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1701-1702
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• 2009

• Bulletin of the Korean Chemical Society
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• 제19권6호
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• pp.667-671
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• 1998

A series of 1-aryl-lH-pyrazolo[4,3-c]quinolines and 2-aryl-2H-pyrazolo[4,3-c]quinolines are prepared by reacting 3-acyl-4-chloroquinolines in ethanol or 3-acyl-4(lH)-quinolone in acetic acid with appropriate hydrazines as possible anti-ulcer agents. A regiospecific synthesis of 1-aryl-lH-pyrazolo[4,3-c]quinolines is also achieved. The central pyridine ring could be easily reduced by catalytic hydrogenation.

• Nuclear Engineering and Technology
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• 제51권2호
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• pp.518-525
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• 2019

The mechanical and corrosion behavior of the Russian zirconium fuel cladding alloy E110, predominantly used in VVERs, has been investigated for many decades. The recent commercialization of a new, optimized E110 alloy, produced on a sponge zirconium basis, gave the opportunity to compare the mechanical properties of the old and the new E110 fuel claddings. Axial and tangential tensile test experiments were performed with samples from both claddings in the MTA EK. Due to the anisotropy of the cladding tubes, the axial tensile strength was 10-15% higher than the tangential (measured by ring tensile tests). The tensile strength of the new E110G alloy was 11% higher than that of the E110 cladding at room temperature. Some samples underwent chemical treatment - slight oxidation in steam or hydrogenation - or heat treatment - in argon atmosphere at temperatures between 600 and $1000^{\circ}C$. The heat treatment during the oxidation had more significant effect on the tensile strength of the claddings than the oxidation itself, which lowered the tensile strength as the thickness of the metal decreased. The hydrogenation of the cladding samples slightly lowered the tensile strength and the samples but they remained ductile even at room temperature.